Medical device inserters and processes of inserting and using medical devices

ABSTRACT

An apparatus including a sheath defining a distal surface for placement on a skin surface, a device support movable between a proximal and distal position, and adapted to support a medical device, a sharp support movable between a proximal position and a distal position and adapted to support a sharp for inserting the medical device under the skin surface and extending through a portion of the device support, a handle movable between a proximal position and a distal position relative to the sheath and adapted to urge the device support and the sharp support from a proximal to a distal position to insert the sharp under the skin surface, and a driver for advancing the sharp support towards the proximal position when the sharp support reaches the distal position.

RELATED APPLICATIONS

The present application claims the benefit of U.S. ProvisionalApplication Nos. 61/317,243, filed Mar. 24, 2010; 61/345,562, filed May17, 2010; 61/361,374, filed Jul. 2, 2010 61/411,262, filed Nov. 8, 2010,the disclosures of which are incorporated herein by reference for allpurposes.

INCORPORATION BY REFERENCE

Patents, applications and/or publications described herein, includingthe following patents, applications and/or publications are incorporatedherein by reference for all purposes: U.S. Pat. Nos. 4,545,382;4,711,245; 5,262,035; 5,262,305; 5,264,104; 5,320,715; 5,356,786;5,509,410; 5,543,326; 5,593,852; 5,601,435; 5,628,890; 5,820,551;5,822,715; 5,899,855; 5,918,603; 6,071,391; 6,103,033; 6,120,676;6,121,009; 6,134,461; 6,143,164; 6,144,837; 6,161,095; 6,175,752;6,270,455; 6,284,478; 6,299,757; 6,338,790; 6,377,894; 6,461,496;6,503,381; 6,514,460; 6,514,718; 6,540,891; 6,560,471; 6,579,690;6,591,125; 6,592,745; 6,600,997; 6,605,200; 6,605,201; 6,616,819;6,618,934; 6,650,471; 6,654,625; 6,676,816; 6,730,200; 6,736,957;6,746,582; 6,749,740; 6,764,581; 6,773,671; 6,881,551; 6,893,545;6,932,892; 6,932,894; 6,942,518; 7,041,468; 7,167,818; and 7,299,082;7,381,184; 7,740,581; 7,811,231 U.S. Published Application Nos.2005/0182306; 2006/0091006; 2007/0056858; 2007/0068807; 2007/0095661;2007/0108048; 2007/0149873; 2007/0149875; 2007/0199818; 2007/0227911;2007/0233013; 2008/0058625; 2008/0064937; 2008/0066305; 2008/0071157;2008/0071158; 2008/0081977; 2008/0102441; 2008/0148873; 2008/0161666;2008/0179187; 2008/0267823; 2008/0319295; 2008/0319296; 2009/0018425;2009/0247857; 2009/0257911, 2009/0281406; 2009/0294277; 2009/0054748;2009/0054749; 2010/0030052; 2010/0065441; 2010/0081905; 2010/0081909;2010/0213057; 2010/0325868; 2010/0326842; 2010/0326843; 2010/0331643;2011/0046466; U.S. patent application Ser. Nos. 12/624,767; 12/625,185;12/625,208; 12/625,524; 12/625,525; 12/625,528; 12/628,177; 12/628,198;12/628,201; 12/628,203; 12/628,210; 12/698,124; 12/698,129; 12/699,653;12/699,844; 12/714,439; 12/730,193; 12/794,721; 12/807,278; 12/842,013;12/870,818; 12/871,901; 12/873,301; 12/873,302; 13/011,897; and U.S.Provisional Application Nos. 61/238,646; 61/246,825; 61/247,516;61/249,535; 61/317,243; 61/325,155; 61/345,562; and 61/359,265.

BACKGROUND

The detection and/or monitoring of glucose levels or other analytes,such as lactate, oxygen, A1C, or the like, in certain individuals isvitally important to their health. For example, the monitoring ofglucose is particularly important to individuals with diabetes.Diabetics generally monitor glucose levels to determine if their glucoselevels are being maintained within a clinically safe range, and may alsouse this information to determine if and/or when insulin is needed toreduce glucose levels in their bodies or when additional glucose isneeded to raise the level of glucose in their bodies.

Growing clinical data demonstrates a strong correlation between thefrequency of glucose monitoring and glycemic control. Despite suchcorrelation, many individuals diagnosed with a diabetic condition do notmonitor their glucose levels as frequently as they should due to acombination of factors including convenience, testing discretion, painassociated with glucose testing, and cost.

Devices have been developed for the automatic monitoring of analyte(s),such as glucose, in bodily fluid such as in the blood stream or ininterstitial fluid (“ISF”), or other biological fluid. Some of theseanalyte measuring devices are configured so that at least a portion ofthe devices are positioned below a skin surface of a user, e.g., in ablood vessel or in the subcutaneous tissue of a user, so that themonitoring is accomplished in vivo.

With the continued development of analyte monitoring devices andsystems, there is a need for such analyte monitoring devices, systems,and methods, as well as for processes for manufacturing analytemonitoring devices and systems that are cost effective, convenient, andwith reduced pain, provide discreet monitoring to encourage frequentanalyte monitoring to improve glycemic control.

SUMMARY

In certain embodiments, an apparatus for inserting a medical device intothe skin of a subject is provided, which includes a sheath defining adistal surface for placement on the skin of the subject; a devicesupport movable between a proximal and distal position, and adapted tosupport the medical device; a sharp support movable between a proximaland a distal position and adapted to support a sharp for inserting themedical device into the skin of the subject and extending through aportion of said device support, the device support comprising a firstengagement member for releasably coupling the sharp support to thedevice support and a second engagement member for engaging the medicaldevice; a handle movable between a proximal position and a distalposition relative to the sheath and adapted to urge the device supportand the sharp support from a proximal to a distal position to insert thesharp into the skin of the subject; and a driver for advancing the sharpsupport towards the proximal position when the sharp support reaches thedistal position.

In some embodiments, the handle and sheath define an interlockingconfiguration which prevents relative movement of the handle withrespect to the sheath which is overcome by a force applied to thehandle. In some embodiment, the second engagement member includes one ormore movable arms for engaging the device. The one or more movable armsare normally biased in a position spaced apart from the medical devicein some embodiments. The one or more movable arms may be maintained inengagement with the medical device when the device support is in theproximal position. In some embodiments, the one or more movable armsreturn to the configuration space apart from the medical device when thedevice support is in the distal position.

In some embodiments, the engagement member is released from the sharpsupport when the device support reaches a distal position. In someembodiments, the engagement member is maintained in engagement with thedevice support by a portion of the sheath.

In some embodiments, a stop is provided to maintain the device supportin the proximal position.

In some embodiments, the handle includes a button disposed within anouter housing. The handle may be flush with the top of the outer housingin an initial configuration when the medical device is supported in thedevice support, and the handle may protrude above the outer housingafter the medical device is released from the device support.

In some embodiments, the medical device is an analyte sensor.

A method for using a medical device is provided which includes providingan apparatus comprising a sheath defining a distal surface, a devicesupport adapted to support the medical device, a sharp support adaptedto support a sharp extending through a portion of said device support, ahandle movable relative to the sheath, and a driver for displacing thesharp support; disposing the distal surface of the sheath on the skin ofthe subject; and displacing the handle in a first longitudinaldirection; displacing the sharp support in the first longitudinaldirection, the sharp support displacing the sharp and the medicaldevice. The method further includes inserting the sharp into the skin ofthe subject; delivering the medical device to the subject; releasing thedriver; and displacing the sharp in the second longitudinal direction bythe driver.

In some embodiments, the method further includes locking at least aportion of the sheath to the handle.

These and other features, objects, and advantages of the disclosedsubject matter will become apparent to those persons skilled in the artupon reading the detailed description as more fully described below.

BRIEF DESCRIPTION OF THE DRAWINGS

A detailed description of various aspects, features, and embodiments ofthe subject matter described herein is provided with reference to theaccompanying drawings, which are briefly described below. The drawingsare illustrative and are not necessarily drawn to scale, with somecomponents and features being exaggerated for clarity. The drawingsillustrate various aspects and features of the present subject matterand may illustrate one or more embodiment(s) or example(s) of thepresent subject matter in whole or in part.

FIG. 1 illustrates an analyte monitoring system for real time analyte(e.g., glucose) measurement, data acquisition and/or processing incertain embodiments;

FIG. 2 is a view of an electrochemical sensor in accordance with anembodiment of the disclosed subject matter;

FIG. 3 is a view of the electrochemical sensor of FIG. 2 in a foldedconfiguration in accordance with the disclosed subject matter;

FIG. 4 is a perspective view of an embodiment of an inserter inaccordance with one embodiment of the disclosed subject matter;

FIGS. 5-6 are perspective views of the inserter of FIG. 4 in accordancewith the disclosed subject matter;

FIGS. 7-8 are sectional, perspective views of the inserter of FIG. 4 inaccordance with the disclosed subject matter;

FIGS. 9-10 are schematic views of a needle hub in accordance with oneembodiment of the disclosed subject matter;

FIG. 11 is a distal end view of a sharp in accordance with oneembodiment of the disclosed subject matter;

FIG. 12 is a side view of a sharp in accordance with one embodiment ofthe disclosed subject matter;

FIG. 13 is a side view of a sharp in accordance with one embodiment ofthe disclosed subject matter;

FIG. 14 is a perspective view of a sharp in accordance with oneembodiment of the disclosed subject matter;

FIGS. 14A-B are top views of a sharp in accordance with one embodimentof the disclosed subject matter;

FIG. 14C is a side view of a sharp in accordance with one embodiment ofthe disclosed subject matter;

FIG. 15 is a schematic view of an alternate embodiment for forming asharp to be used in an inserter in accordance with one embodiment of thedisclosed subject matter;

FIG. 16 is a perspective view of an inserter in accordance with oneembodiment of the disclosed subject matter;

FIG. 17 is a perspective view with parts separated of an inserter inaccordance with one embodiment of the disclosed subject matter;

FIG. 17A is an enlarged perspective view of a portion of an inserter inaccordance with one embodiment of the disclosed subject matter.

FIG. 18 is an enlarged sectional view with parts separated of aninserter in accordance with one embodiment of the disclosed subjectmatter;

FIGS. 19-21 depict an alternative method for retaining a sharp andsensor within the on body housing;

FIG. 22 is a sectional, perspective views of the inserter of FIG. 4 inaccordance with the disclosed subject matter;

FIGS. 23-24 are perspective views of the inserter of FIG. 4 inaccordance with the disclosed subject matter;

FIGS. 25-26 are perspective views of another embodiment of an inserterin accordance with the disclosed subject matter;

FIGS. 27-32 are perspective views of components of the inserter of FIG.25 in accordance with the disclosed subject matter;

FIG. 33 is a sectional view of the inserter of FIG. 25 in accordancewith the disclosed subject matter;

FIG. 34 is a sectional, perspective view of the inserter of FIG. 25 inaccordance with the disclosed subject matter;

FIG. 35 is a perspective view of the inserter of FIG. 25 in accordancewith the disclosed subject matter;

FIGS. 36-37 are sectional, perspective views of the inserter of FIG. 25in accordance with the disclosed subject matter;

FIGS. 38-39 are perspective views of the inserter of FIG. 25 inaccordance with the disclosed subject matter;

FIGS. 40-41 are perspective views of another embodiment of an inserterin accordance with the disclosed subject matter;

FIGS. 42-46 are perspective views of components of the inserter of FIG.40 in accordance with the disclosed subject matter;

FIG. 47 is a sectional views of the inserter of FIG. 40 in accordancewith the disclosed subject matter;

FIGS. 48-50 are sectional, perspective views of the inserter of FIG. 40in accordance with the disclosed subject matter;

FIG. 51 is a cross-sectional view of another inserter in accordance withthe disclosed subject matter;

FIG. 52 is an exploded perspective view of the inserter of FIG. 51 inaccordance with the disclosed subject matter;

FIGS. 53 and 54 are side views of the inserter of FIG. 51 showing theassembly of various components in accordance with the disclosed subjectmatter;

FIGS. 55-60 are perspective views of the inserter of FIG. 51 showing theassembly of various components in accordance with the disclosed subjectmatter;

FIGS. 61-65 are cross-sectional views of the inserter of FIG. 51 inaccordance with the disclosed subject matter;

FIGS. 66-68 illustrate a process for utilizing a sterilized versions ofthe inserter of FIG. 51 in accordance with the disclosed subject matter;

FIG. 69-72 illustrates an alternate process for utilizing a sterilizedversions of the inserter of FIG. 51 in accordance with the disclosedsubject matter;

FIG. 73 is a perspective view of another inserter in accordance with thedisclosed subject matter;

FIG. 74 is a perspective view of a component of the inserter of FIG. 73in accordance with the disclosed subject matter;

FIG. 75 is a cross-sectional view of a component of the inserter of FIG.73 in accordance with the disclosed subject matter;

FIGS. 76-80 are perspective views of components of the inserter of FIG.73 in accordance with the disclosed subject matter;

FIGS. 81-87 are cross-sectional views of the inserter of FIG. 73 inaccordance with the disclosed subject matter;

FIGS. 88-90 illustrate a process for utilizing a sterilized version ofthe inserter of FIG. 73 in accordance with the disclosed subject matter;

FIG. 91 is a perspective view of another inserter in accordance with thedisclosed subject matter;

FIGS. 92-99 are additional views of the components of the inserter ofFIG. 91 in accordance with the disclosed subject matter;

FIGS. 100-106 are cross-sectional views of the inserter of FIG. 91 inaccordance with the disclosed subject matter;

FIGS. 107-108 are views of an alternate embodiment of the inserter ofFIG. 91 in accordance with the disclosed subject matter; and

FIGS. 109-134 are views of an alternate embodiment of the inserter ofFIG. 73 in accordance with the disclosed subject matter.

FIGS. 135-136 illustrate bottom and top views, respectively, of themedical device carrier in accordance with the disclosed subject matter.

FIGS. 137-138 illustrate the sheath component of an inserter inaccordance with the disclosed subject matter.

FIGS. 139-140 illustrate, in cross section, the progressive advancementof the on body housing in accordance with the disclosed subject matter.

FIGS. 141-144 illustrate the advancement of the on body housing withinan inserter in accordance with the disclosed subject matter.

FIGS. 145 a-147 b illustrate the attachment of a two piece on bodyhousing in accordance with the disclosed subject matter.

FIG. 148 illustrates a two-piece on body housing in accordance with thedisclosed subject matter.

FIG. 149 illustrates another two-piece on body housing in accordancewith the disclosed subject matter.

FIGS. 150-156 illustrate the advancement of a two piece on body housingin accordance with the disclosed subject matter.

FIGS. 157-158 illustrate the assembly of the two piece on body housingin accordance with the disclosed subject matter.

FIGS. 159-164 illustrate two piece on body housings in accordance withthe disclosed subject matter.

DETAILED DESCRIPTION OF THE EMBODIMENTS

A detailed description of the disclosure is provided herein. It shouldbe understood, in connection with the following description, that thesubject matter is not limited to particular embodiments described, asthe particular embodiments of the subject matter may, of course, vary.It is also to be understood that the terminology used herein is for thepurpose of describing particular embodiments only, and is not intendedto be limiting, since the scope of the disclosed subject matter will belimited only by the appended claims.

Where a range of values is provided, it is understood that eachintervening value between the upper and lower limit of that range, andany other stated or intervening value in that stated range, isencompassed within the disclosed subject matter. Every range stated isalso intended to specifically disclose each and every “subrange” of thestated range. That is, each and every range smaller than the outsiderange specified by the outside upper and outside lower limits given fora range, whose upper and lower limits are within the range from saidoutside lower limit to said outside upper limit (unless the contextclearly dictates otherwise), is also to be understood as encompassedwithin the disclosed subject matter, subject to any specificallyexcluded range or limit within the stated range. Where a range is statedby specifying one or both of an upper and lower limit, ranges excludingeither or both of those stated limits, or including one or both of them,are also encompassed within the disclosed subject matter, regardless ofwhether or not words such as “from,” “to,” “through,” or “including” areor are not used in describing the range.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this disclosed subject matter belongs. Although anymethods and materials similar or equivalent to those described hereincan also be used in the practice or testing of the present disclosedsubject matter, this disclosure may specifically mention certainexemplary methods and materials.

All publications mentioned in this disclosure are, unless otherwisespecified, incorporated by reference herein for all purposes, includingwithout limitation to disclose and describe the methods and/or materialsin connection with which the publications are cited.

The publications discussed herein are provided solely for theirdisclosure prior to the filing date of the present application. Nothingherein is to be construed as an admission that the present disclosedsubject matter is not entitled to antedate such publication by virtue ofprior invention. Further, the dates of publication provided may bedifferent from the actual publication dates, which may need to beindependently confirmed.

As used herein and in the appended claims, the singular forms “a,” “an,”and “the” include plural referents unless the context clearly dictatesotherwise.

Nothing contained in the Abstract or the Summary should be understood aslimiting the scope of the disclosure. The Abstract and the Summary areprovided for bibliographic and convenience purposes and due to theirformats and purposes should not be considered comprehensive.

As will be apparent to those of skill in the art upon reading thisdisclosure, each of the individual embodiments described and illustratedherein has discrete components and features which may be readilyseparated from or combined with the features of any of the other severalembodiments without departing from the scope or spirit of the presentdisclosed subject matter. Any recited method can be carried out in theorder of events recited, or in any other order which is logicallypossible.

Reference to a singular item includes the possibility that there areplural of the same item present. When two or more items (for example,elements or processes) are referenced by an alternative “or,” thisindicates that either could be present separately or any combination ofthem could be present together except where the presence of onenecessarily excludes the other or others.

Generally, embodiments of the present disclosure relate to an apparatusfor inserting a medical device at least partially into the skin of thepatient. Some embodiments relate to in vivo methods and devices fordetecting at least one analyte such as glucose in body fluid.Accordingly, embodiments include in vivo analyte sensors configured sothat at least a portion of the sensor is positioned in the body of auser (e.g., within the ISF), to obtain information about at least oneanalyte of the body, e.g., transcutaneously positioned in user's body.In certain embodiments, an in vivo analyte sensor is coupled to anelectronics unit that is maintained on the body of the user to processinformation obtained from the sensor.

In certain embodiments, analyte information is communicated from a firstdevice such as an on body electronics unit to a second device which mayinclude user interface features, including a display, and/or the like.Information may be communicated from the first device to the seconddevice automatically and/or continuously when the analyte information isavailable, or may not be communicated automatically and/or continuously,but rather stored or logged in a memory of the first device.Accordingly, in many embodiments of the system, analyte informationderived by the sensor/on body electronics (for example, on bodyelectronics) is made available in a user-usable or viewable form onlywhen queried by the user such that the timing of data communication isselected by the user. In some embodiments, the display of information isselected by the user, while the timing of data communication is not.

In this manner, analyte information is only provided or evident to auser (provided at a user interface device) in some embodiments whendesired by the user even though an in vivo analyte sensor automaticallyand/or continuously monitors the analyte level in vivo, i.e., the sensorautomatically monitors analyte such as glucose on a pre-defined timeinterval over its usage life. For example, an analyte sensor may bepositioned in vivo and coupled to on body electronics for a givensensing period, e.g., about 14 days. In certain embodiments, thesensor-derived analyte information is automatically communicated fromthe sensor electronics assembly to a remote monitor device or displaydevice for output to a user throughout the 14 day period according to aschedule programmed at the on body electronics (e.g., about every 1minute or about every 5 minutes or about every 10 minutes, or the like).In certain embodiments, sensor-derived analyte information is onlycommunicated from the sensor electronics assembly to a remote monitordevice or display device at user-determined times, e.g., whenever a userdecides to check analyte information. At such times, a communicationssystem is activated and sensor-derived information is then sent from theon body electronics to the remote device or display device.

In still other embodiments, the information may be communicated from thefirst device to the second device automatically and/or continuously whenthe analyte information is available, and the second device stores orlogs the received information without presenting or outputting theinformation to the user. In such embodiments, the information isreceived by the second device from the first device when the informationbecomes available (e.g., when the sensor detects the analyte levelaccording to a time schedule). However, the received information isinitially stored in the second device and only output to a userinterface or an output component of the second device (e.g., display)upon detection of a request for the information on the second device.

Accordingly, in certain embodiments an inserter as described herein isused to place a sensor electronics assembly on the body so that at leasta portion of the in vivo sensor is in contact with bodily fluid such asISF. Once the sensor is electrically coupled to the electronics unit,sensor derived analyte information may be communicated from the on bodyelectronics to a display device on-demand by powering on the displaydevice (or it may be continually powered), and executing a softwarealgorithm stored in and accessed from a memory of the display device, togenerate one or more request commands, control signal or data packet tosend to the on body electronics. The software algorithm executed under,for example, the control of the microprocessor or application specificintegrated circuit (ASIC) of the display device may include routines todetect the position of the on body electronics relative to the displaydevice to initiate the transmission of the generated request command,control signal and/or data packet.

Display devices may also include programming stored in memory forexecution by one or more microprocessors and/or ASICs to generate andtransmit the one or more request command, control signal or data packetto send to the on body electronics in response to a user activation ofan input mechanism on the display device such as depressing a button onthe display device, triggering a soft button associated with the datacommunication function, and so on. The input mechanism may bealternatively or additionally provided on or in the on body electronicswhich may be configured for user activation. In certain embodiments,voice commands or audible signals may be used to prompt or instruct themicroprocessor or ASIC to execute the software routine(s) stored in thememory to generate and transmit the one or more request command, controlsignal or data packet to the on body device. In the embodiments that arevoice activated or responsive to voice commands or audible signals, onbody electronics and/or display device includes a microphone, a speaker,and processing routines stored in the respective memories of the on bodyelectronics and/or the display device to process the voice commandsand/or audible signals. In certain embodiments, positioning the on bodyelectronics and the display device within a predetermined distance(e.g., close proximity) relative to each other initiates one or moresoftware routines stored in the memory of the display device to generateand transmit a request command, control signal or data packet.

Different types and/or forms and/or amounts of information may be sentfor each on demand reading, including but not limited to one or more ofcurrent analyte level information (i.e., real time or the most recentlyobtained analyte level information temporally corresponding to the timethe reading is initiated), rate of change of an analyte over apredetermined time period, rate of the rate of change of an analyte(acceleration in the rate of change), historical analyte informationcorresponding to analyte information obtained prior to a given readingand stored in memory of the assembly. Some or all of real time,historical, rate of change, rate of rate of change (such as accelerationor deceleration) information may be sent to a display device for a givenreading. In certain embodiments, the type and/or form and/or amount ofinformation sent to a display device may be preprogrammed and/orunchangeable (e.g., preset at manufacturing), or may not bepreprogrammed and/or unchangeable so that it may be selectable and/orchangeable in the field one or more times (e.g., by activating a switchof the system, etc). Accordingly, in certain embodiments, for each ondemand reading, a display device will output a current (real time)sensor-derived analyte value (e.g., in numerical format), a current rateof analyte change (e.g., in the form of an analyte rate indicator suchas an arrow pointing in a direction to indicate the current rate), andanalyte trend history data based on sensor readings acquired by andstored in memory of on body electronics (e.g., in the form of agraphical trace). Additionally, the on skin or sensor temperaturereading or measurement associated with each on demand reading may becommunicated from the on body electronics to the display device. Thetemperature reading or measurement, however, may not be output ordisplayed on the display device, but rather, used in conjunction with asoftware routine executed by the display device to correct or compensatethe analyte measurement output to the user on the display device.

As described, embodiments include inserters for in vivo analyte sensorsand on body electronics that together provide body wearable sensorelectronics assemblies. In certain embodiments, in vivo analyte sensorsare fully integrated with on body electronics (fixedly connected duringmanufacture), while in other embodiments they are separate butconnectable post manufacture (e.g., before, during or after sensorinsertion into a body). On body electronics may include an in vivoglucose sensor, electronics, battery, and antenna encased (except forthe sensor portion that is for in vivo positioning) in a waterproofhousing that includes or is attachable to an adhesive pad. In certainembodiments, the housing withstands immersion in about one meter ofwater for up to at least 30 minutes. In certain embodiments, the housingwithstands continuous underwater contact, e.g., for longer than about 30minutes, and continues to function properly according to its intendeduse, e.g., without water damage to the housing electronics where thehousing is suitable for water submersion.

Embodiments include sensor insertion devices, which also may be referredto herein as sensor delivery units, or the like. Insertion devices mayretain on body electronics assemblies completely in an interiorcompartment, i.e., an insertion device may be “pre-loaded” with on bodyelectronics assemblies during the manufacturing process (e.g., on bodyelectronics may be packaged in a sterile interior compartment of aninsertion device). In such embodiments, insertion devices may formsensor assembly packages (including sterile packages) for pre-use or newon body electronics assemblies, and insertion devices configured toapply on body electronics assemblies to recipient bodies.

Embodiments include portable handheld display devices, as separatedevices and spaced apart from an on body electronics assembly, thatcollect information from the assemblies and provide sensor derivedanalyte readings to users. Such devices may also be referred to asmeters, readers, monitors, receivers, human interface devices,companions, or the like. Certain embodiments may include an integratedin vitro analyte meter. In certain embodiments, display devices includeone or more wired or wireless communications ports such as USB, serial,parallel, or the like, configured to establish communication between adisplay device and another unit (e.g., on body electronics, power unitto recharge a battery, a PC, etc). For example, a display devicecommunication port may enable charging a display device battery with arespective charging cable and/or data exchange between a display deviceand its compatible informatics software.

Compatible informatics software in certain embodiments include, forexample, but not limited to stand alone or network connection enableddata management software program, resident or running on a displaydevice, personal computer, a server terminal, for example, to performdata analysis, charting, data storage, data archiving and datacommunication as well as data synchronization. Informatics software incertain embodiments may also include software for executing fieldupgradable functions to upgrade firmware of a display device and/or onbody electronics unit to upgrade the resident software on the displaydevice and/or the on body electronics unit, e.g., with versions offirmware that include additional features and/or include software bugsor errors fixed, etc. Embodiments may include a haptic feedback featuresuch as a vibration motor or the like, configured so that correspondingnotifications (e.g., a successful on-demand reading received at adisplay device), may be delivered in the form of haptic feedback.

Embodiments include programming embedded on a computer readable medium,i.e., computer-based application software (may also be referred toherein as informatics software or programming or the like) thatprocesses analyte information obtained from the system and/or userself-reported data. Application software may be installed on a hostcomputer such as a mobile telephone, PC, an Internet-enabled humaninterface device such as an Internet-enabled phone, personal digitalassistant, or the like, by a display device or an on body electronicsunit. Informatics programming may transform data acquired and stored ona display device or on body unit for use by a user.

Embodiments of the subject disclosure are described primarily withrespect to glucose monitoring devices and systems, and methods ofglucose monitoring, for convenience only and such description is in noway intended to limit the scope of the disclosure. It is to beunderstood that the analyte monitoring system may be configured tomonitor a variety of analytes at the same time or at different times.

As described in detail below, embodiments include devices, systems, kitsand/or methods to monitor one or more physiological parameters such as,for example, but not limited to, analyte levels, temperature levels,heart rate, user activity level, over a predetermined monitoring timeperiod. Also provided are methods of manufacturing. Predeterminedmonitoring time periods may be less than about 1 hour, or may includeabout 1 hour or more, e.g., about a few hours or more, e.g., about a fewdays of more, e.g., about 3 or more days, e.g., about 5 days or more,e.g., about 7 days or more, e.g., about 10 days or more, e.g., about 14days or more, e.g., about several weeks, e.g., about 1 month or more. Incertain embodiments, after the expiration of the predeterminedmonitoring time period, one or more features of the system may beautomatically deactivated or disabled at the on body electronicsassembly and/or display device.

For example, a predetermined monitoring time period may begin withpositioning the sensor in vivo and in contact with a body fluid such asISF, and/or with the initiation (or powering on to full operationalmode) of the on body electronics. Initialization of on body electronicsmay be implemented with a command generated and transmitted by a displaydevice in response to the activation of a switch and/or by placing thedisplay device within a predetermined distance (e.g., close proximity)to the on body electronics, or by user manual activation of a switch onthe on body electronics unit, e.g., depressing a button, or suchactivation may be caused by the insertion device, e.g., as described inU.S. patent application Ser. No. 12/698,129 filed on Feb. 1, 2010 andU.S. Provisional Application Nos. 61/238,646, 61/246,825, 61/247,516,61/249,535, 61/317,243, 61/345,562, and 61/361,374, the disclosures ofeach of which are incorporated herein by reference for all purposes.

When initialized in response to a received command from a displaydevice, the on body electronics retrieves and executes from its memorysoftware routine to fully power on the components of the on bodyelectronics, effectively placing the on body electronics in fulloperational mode in response to receiving the activation command fromthe display device. For example, prior to the receipt of the commandfrom the display device, a portion of the components in the on bodyelectronics may be powered by its internal power supply such as abattery while another portion of the components in the on bodyelectronics may be in powered down or maintained in a low power stateincluding no power state, inactive mode, or all components may be in aninactive, powered down mode. Upon receipt of the command, the remainingportion (or all) of the components of the on body electronics isswitched to active, fully operational mode.

Embodiments of on body electronics may include one or more printedcircuit boards with electronics including control logic implemented inASIC, microprocessors, memory, and the like, and transcutaneouslypositionable analyte sensors forming a single assembly. On bodyelectronics may be configured to provide one or more signals or datapackets associated with a monitored analyte level upon detection of adisplay device of the analyte monitoring system within a predeterminedproximity for a period of time (for example, about 2 minutes, e.g., 1minute or less, e.g., about 30 seconds or less, e.g., about 10 secondsor less, e.g., about 5 seconds or less, e.g., about 2 seconds or less)and/or until a confirmation, such as an audible and/or visual and/ortactile (e.g., vibratory) notification, is output on the display deviceindicating successful acquisition of the analyte related signal from theon body electronics. A distinguishing notification may also be outputfor unsuccessful acquisition in certain embodiments.

In certain embodiments, the monitored analyte level may be correlatedand/or converted to glucose levels in blood or other fluids such as ISF.Such conversion may be accomplished with the on body electronics, but inmany embodiments will be accomplished with display device electronics.In certain embodiments, glucose level is derived from the monitoredanalyte level in the ISF.

Analyte sensors may be insertable into a vein, artery, or other portionof the body containing analyte. In certain embodiments, analyte sensorsmay be positioned in contact with ISF to detect the level of analyte,where the detected analyte level may be used to infer the user's glucoselevel in blood or interstitial tissue.

Embodiments include transcutaneous sensors and also wholly implantablesensors and wholly implantable assemblies in which a single assemblyincluding the analyte sensor and electronics are provided in a sealedhousing (e.g., hermetically sealed biocompatible housing) forimplantation in a user's body for monitoring one or more physiologicalparameters.

Embodiments include analyte monitors that are provided in small,lightweight, battery-powered and electronically-controlled systems. Suchsystems may be configured to detect physical parameters of subjects,such as signals indicative of in vivo analyte levels using anelectrochemical sensor, and collect such signals, with or withoutprocessing. Any suitable measurement technique may be used to obtainsignals from the sensors, e.g., may detect current, may employpotentiometry, etc. Techniques may include, but are not limited toamperometry, coulometry, and voltammetry. In some embodiments, sensingsystems may be optical, colorimetric, and the like. In some embodiments,the portion of the system that performs this initial processing may beconfigured to provide the raw or at least initially processed data toanother unit for further collection and/or processing. Such provision ofdata may be affected, for example, by a wired connection, such as anelectrical, or by a wireless connection, such as an IR or RF connection.

In certain systems, the analyte sensor is in communication with on bodyelectronics. The on-body unit may include a housing in which the on bodyelectronics and at least a portion of the sensor are received.

Certain embodiments are modular. The on-body unit may be separatelyprovided as a physically distinct assembly from a monitor unit, e.g.,which displays or otherwise indicates analyte levels to a user. Theon-body unit may be configured to provide the analyte levels detected bythe sensor and/or other information (such as temperature, sensor life,etc.) over a communication link to the monitor unit. The monitor unit,in some embodiments, may include, e.g., a mobile telephone device, an invitro glucose meter, a personal digital assistant, or other consumerelectronics such as MP3 device, camera, radio, personal computer, etc.,or other communication-enabled data-processing device.

The display unit may perform a variety of functions such as but notlimited to data storage and/or processing and/or analysis and/orcommunication, etc., on the received analyte data to generateinformation pertaining to the monitored analyte levels and/or processthe other information. The monitor unit may incorporate a displayscreen, which can be used, for example, to display measured analytelevels, and/or an audio component such as a speaker to audibly provideinformation to a user, and/or a vibration device to provide tactilefeedback to a user. It is also useful for a user of ananalyte-monitoring system to be able to see trend indications (includingthe magnitude and direction of any ongoing trend, e.g., the rate ofchange of an analyte or other parameter, and the amount of time asubject is above and/or below a threshold, such as a hypoglycemic and/orhyperglycemic threshold, etc.); such data may be displayed eithernumerically, or by a visual indicator such as an arrow that may vary invisual attributes, like size, shape, color, animation, or direction. Themonitor unit may further be adapted to receive information from or aboutan in vitro analyte test strip, which may be manually or automaticallyentered into the monitor unit. In some embodiments a monitor unit mayincorporate an in vitro analyte test strip port and related electronicsin order to be able to make discrete (e.g., blood glucose) measurementsusing an in vitro test strip (see, e.g., U.S. Pat. No. 6,175,752, thedisclosure of which is incorporated by reference herein for allpurposes).

The modularity of these systems may vary where one or more componentsmay be constructed to be single use and one or more may be constructedto be re-useable. In some embodiments the sensor is designed to beattachable and detachable from the on body electronics (and the on-bodyunit may be reusable), e.g., so that one or more of the components maybe reused one or more times, while in other embodiments, the sensor andon body electronics may be provided as an integrated, undetachablepackage, which may be designed to be disposable after use, i.e., notre-used.

Embodiments of In Vivo Monitoring Systems

For purpose of illustration, and not limitation, the inserters describedherein may be used in connection with an exemplary analyte monitoringsystem as depicted in FIG. 1. It is understood that the insertersdescribed herein may be used with any medical device on its own or inconnection with a system. FIG. 1 shows an exemplary in vivo-basedanalyte monitoring system 100 in accordance with embodiments of thepresent disclosure. As shown, in certain embodiments, analyte monitoringsystem 100 includes on body electronics 1100 electrically coupled to invivo analyte sensor 14 (a proximal portion of which is shown in FIG. 1),and attached to adhesive layer 218 for attachment on a skin surface onthe body of a user. On body electronics 1100 includes on body housing122 that defines an interior compartment.

Also shown in FIG. 1 is insertion device 200 (or insertion devices 300,400, 2400, 2500, 2700, 3700 described herein) that, when operated,transcutaneously positions a portion of analyte sensor 14 through a skinsurface and in fluid contact with ISF, and positions on body electronics1100 and adhesive layer 218 on a skin surface, as will be described ingreater detail herein. In certain embodiments, on body electronics 1100,analyte sensor 14 and adhesive layer 218 are sealed within the housingof insertion device 200 before use, and in certain embodiments, adhesivelayer 218 is also sealed within the housing or the adhesive layer canprovide a seal for preserving the sterility of the apparatus. Additionaldetails regarding insertion devices are discussed, e.g., in U.S. patentapplication Ser. No. 12/698,129 and U.S. Provisional Application Nos.61/238,646, 61/246,825, 61/247,516, 61/249,535, and 61/345,562, thedisclosures of each of which are incorporated herein by reference forall purposes.

Referring back to the FIG. 1, analyte monitoring system 100 includesdisplay device 1200 which includes a display 1220 to output informationto the user, an input component 1210 such as a button, actuator, a touchsensitive switch, a capacitive switch, pressure sensitive switch, jogwheel or the like, to input data or command to display device 1200 orotherwise control the operation of display device 1200. It is noted thatsome embodiments may include display-less devices or devices without anyuser interface components. These devices may be functionalized to storedata as a data logger and/or provide a conduit to transfer data from onbody electronics and/or a display-less device to another device and/orlocation. Embodiments will be described herein as display devices forexemplary purposes which are in no way intended to limit the embodimentsof the present disclosure. It will be apparent that display-less devicesmay also be used in certain embodiments.

In certain embodiments, on body electronics 1100 may be configured tostore some or all of the monitored analyte related data received fromanalyte sensor 14 in a memory during the monitoring time period, andmaintain it in memory until the usage period ends. In such embodiments,stored data is retrieved from on body electronics 1100 at the conclusionof the monitoring time period, for example, after removing analytesensor 14 from the user by detaching on body electronics 1100 from theskin surface where it was positioned during the monitoring time period.In such data logging configurations, real time monitored analyte levelis not communicated to display device 1200 during the monitoring periodor otherwise transmitted from on body electronics 1100, but rather,retrieved from on body electronics 1100 after the monitoring timeperiod.

In certain embodiments, input component 1210 of display device 1200 mayinclude a microphone and display device 1200 may include softwareconfigured to analyze audio input received from the microphone, suchthat functions and operation of the display device 1200 may becontrolled by voice commands. In certain embodiments, an outputcomponent of display device 1200 includes a speaker for outputtinginformation as audible signals. Similar voice responsive components suchas a speaker, microphone and software routines to generate, process andstore voice driven signals may be provided to on body electronics 1100.

In certain embodiments, display 1220 and input component 1210 may beintegrated into a single component, for example a display that candetect the presence and location of a physical contact touch upon thedisplay such as a touch screen user interface. In such embodiments, theuser may control the operation of display device 1200 by utilizing a setof pre-programmed motion commands, including, but not limited to, singleor double tapping the display, dragging a finger or instrument acrossthe display, motioning multiple fingers or instruments toward oneanother, motioning multiple fingers or instruments away from oneanother, etc. In certain embodiments, a display includes a touch screenhaving areas of pixels with single or dual function capacitive elementsthat serve as LCD elements and touch sensors.

Display device 1200 also includes data communication port 1230 for wireddata communication with external devices such as remote terminal(personal computer) 1700, for example. Example embodiments of the datacommunication port 1230 include USB port, mini USB port, RS-232 port,Ethernet port, Firewire port, or other similar data communication portsconfigured to connect to the compatible data cables. Display device 1200may also include an integrated in vitro glucose meter, including invitro test strip port 1240 to receive an in vitro glucose test strip forperforming in vitro blood glucose measurements.

Referring still to FIG. 1, display 1220 in certain embodiments isconfigured to display a variety of information—some or all of which maybe displayed at the same or different time on display 1220. In certainembodiments the displayed information is user-selectable so that a usercan customize the information shown on a given display screen. Display1220 may include but is not limited to graphical display 1380, forexample, providing a graphical output of glucose values over a monitoredtime period (which may show important markers such as meals, exercise,sleep, heart rate, blood pressure, etc, numerical display 1320, forexample, providing monitored glucose values (acquired or received inresponse to the request for the information), and trend or directionalarrow display 1310 that indicates a rate of analyte change and/or a rateof the rate of analyte change, e.g., by moving locations on display1220.

As further shown in FIG. 1, display 1220 may also include date display1350 providing for example, date information for the user, time of dayinformation display 1390 providing time of day information to the user,battery level indicator display 1330 which graphically shows thecondition of the battery (rechargeable or disposable) of the displaydevice 1200, sensor calibration status icon display 1340 for example, inmonitoring systems that require periodic, routine or a predeterminednumber of user calibration events, notifying the user that the analytesensor calibration is necessary, audio/vibratory settings icon display1360 for displaying the status of the audio/vibratory output or alarmstate, and wireless connectivity status icon display 1370 that providesindication of wireless communication connection with other devices suchas on body electronics, data processing module 1600, and/or remoteterminal 1700. As additionally shown in FIG. 1, display 1220 may furtherinclude simulated touch screen button 1250, 1260 for accessing menus,changing display graph output configurations or otherwise forcontrolling the operation of display device 1200.

Referring back to FIG. 1, in certain embodiments, display 1220 ofdisplay device 1200 may be additionally, or instead of visual display,configured to output alarms notifications such as alarm and/or alertnotifications, glucose values etc, which may be audible, tactile, or anycombination thereof. In one aspect, the display device 1200 may includeother output components such as a speaker, vibratory output componentand the like to provide audible and/or vibratory output indication tothe user in addition to the visual output indication provided on display1220. Further details and other display embodiments can be found in,e.g., U.S. patent application Ser. No. 12/871,901, U.S. provisionalapplication Nos. 61/238,672, 61/247,541, 61/297,625, the disclosures ofeach of which are incorporated herein by reference for all purposes.

After the positioning of on body electronics 1100 on the skin surfaceand analyte sensor 14 in vivo to establish fluid contact with ISF (orother appropriate body fluid), on body electronics 1100 in certainembodiments is configured to wirelessly communicate analyte related data(such as, for example, data corresponding to monitored analyte leveland/or monitored temperature data, and/or stored historical analyterelated data) when on body electronics 1100 receives a command orrequest signal from display device 1200. In certain embodiments, on bodyelectronics 1100 may be configured to at least periodically broadcastreal time data associated with monitored analyte level which is receivedby display device 1200 when display device 1200 is within communicationrange of the data broadcast from on body electronics 1100, i.e., it doesnot need a command or request from a display device to send information.

For example, display device 1200 may be configured to transmit one ormore commands to on body electronics 1100 to initiate data transfer, andin response, on body electronics 1100 may be configured to wirelesslytransmit stored analyte related data collected during the monitoringtime period to display device 1200. Display device 1200 may in turn beconnected to a remote terminal 1700 such as a personal computer andfunctions as a data conduit to transfer the stored analyte levelinformation from the on body electronics 1100 to remote terminal 1700.In certain embodiments, the received data from the on body electronics1100 may be stored (permanently or temporarily) in one or more memory ofthe display device 1200. In certain other embodiments, display device1200 is configured as a data conduit to pass the data received from onbody electronics 1100 to remote terminal 1700 that is connected todisplay device 1200.

Referring still to FIG. 1, also shown in analyte monitoring system 1000are data processing module 1600 and remote terminal 1700. Remoteterminal 1700 may include a personal computer, a server terminal alaptop computer or other suitable data processing devices includingsoftware for data management and analysis and communication with thecomponents in the analyte monitoring system 1000. For example, remoteterminal 1700 may be connected to a local area network (LAN), a widearea network (WAN), or other data network for uni-directional orbi-directional data communication between remote terminal 1700 anddisplay device 1200 and/or data processing module 1600.

Remote terminal 1700 in certain embodiments may include one or morecomputer terminals located at a physician's office or a hospital. Forexample, remote terminal 1700 may be located at a location other thanthe location of display device 1200. Remote terminal 1700 and displaydevice 1200 could be in different rooms or different buildings. Remoteterminal 1700 and display device 1200 could be at least about one mileapart, e.g., at least about 100 miles apart, e.g., at least about 1000miles apart. For example, remote terminal 1700 could be in the same cityas display device 1200, remote terminal 1700 could be in a differentcity than display device 1200, remote terminal 1700 could be in the samestate as display device 1200, remote terminal 1700 could be in adifferent state than display device 1200, remote terminal 1700 could bein the same country as display device 1200, or remote terminal 1700could be in a different country than display device 1200, for example.

In certain embodiments, a separate, optional datacommunication/processing device such as data processing module 1600 maybe provided in analyte monitoring system 1000. Data processing module1600 may include components to communicate using one or more wirelesscommunication protocols such as, for example, but not limited to,infrared (IR) protocol, Bluetooth® protocol, Zigbee protocol, and 802.11wireless LAN protocol. Additional description of communication protocolsincluding those based on Bluetooth® protocol and/or Zigbee protocol canbe found in U.S. Patent Publication No. 2006/0193375 incorporated hereinby reference for all purposes. Data processing module 1600 may furtherinclude communication ports, drivers or connectors to establish wiredcommunication with one or more of display device 1200, on bodyelectronics 1100, or remote terminal 1700 including, for example, butnot limited to USB connector and/or USB port, Ethernet connector and/orport, FireWire connector and/or port, or RS-232 port and/or connector.

In certain embodiments, data processing module 1600 is programmed totransmit a polling or query signal to on body electronics 1100 at apredetermined time interval (e.g., once every minute, once every fiveminutes, or the like), and in response, receive the monitored analytelevel information from on body electronics 1100. Data processing module1600 stores in its memory the received analyte level information, and/orrelays or retransmits the received information to another device such asdisplay device 1200. More specifically in certain embodiments, dataprocessing module 1600 may be configured as a data relay device toretransmit or pass through the received analyte level data from on bodyelectronics 1100 to display device 1200 or a remote terminal (forexample, over a data network such as a cellular or WiFi data network) orboth.

In certain embodiments, on body electronics 1100 and data processingmodule 1600 may be positioned on the skin surface of the user within apredetermined distance of each other (for example, about 1-12 inches, orabout 1-10 inches, or about 1-7 inches, or about 1-5 inches) such thatperiodic communication between on body electronics 1100 and dataprocessing module 1600 is maintained. Alternatively, data processingmodule 1600 may be worn on a belt or clothing item of the user, suchthat the desired distance for communication between the on bodyelectronics 1100 and data processing module 1600 for data communicationis maintained. In a further aspect, the housing of data processingmodule 1600 may be configured to couple to or engage with on bodyelectronics 1100 such that the two devices are combined or integrated asa single assembly and positioned on the skin surface. In furtherembodiments, data processing module 1600 is detachably engaged orconnected to on body electronics 1100 providing additional modularitysuch that data processing module 1600 may be optionally removed orreattached as desired.

Referring again to FIG. 1, in certain embodiments, data processingmodule 1600 is programmed to transmit a command or signal to on bodyelectronics 1100 at a predetermined time interval such as once everyminute, or once every 5 minutes or once every 30 minutes or any othersuitable or desired programmable time interval to request analyterelated data from on body electronics 1100. When data processing module1600 receives the requested analyte related data, it stores the receiveddata. In this manner, analyte monitoring system 1000 may be configuredto receive the continuously monitored analyte related information at theprogrammed or programmable time interval, which is stored and/ordisplayed to the user. The stored data in data processing module 1600may be subsequently provided or transmitted to display device 1200,remote terminal 1700 or the like for subsequent data analysis such asidentifying frequency of periods of glycemic level excursions over themonitored time period, or the frequency of the alarm event occurrenceduring the monitored time period, for example, to improve therapyrelated decisions. Using this information, the doctor, healthcareprovider or the user may adjust or recommend modification to the diet,daily habits and routines such as exercise, and the like.

In another embodiment, data processing module 1600 transmits a commandor signal to on body electronics 1100 to receive the analyte relateddata in response to a user activation of a switch provided on dataprocessing module 1600 or a user initiated command received from displaydevice 1200. In further embodiments, data processing module 1600 isconfigured to transmit a command or signal to on body electronics 1100in response to receiving a user initiated command only after apredetermined time interval has elapsed. For example, in certainembodiments, if the user does not initiate communication within aprogrammed time period, such as, for example about 5 hours from lastcommunication (or 10 hours from the last communication, or 24 hours fromthe last communication), the data processing module 1600 may beprogrammed to automatically transmit a request command or signal to onbody electronics 1100. Alternatively, data processing module 1600 may beprogrammed to activate an alarm to notify the user that a predeterminedtime period of time has elapsed since the last communication between thedata processing module 1600 and on body electronics 1100. In thismanner, users or healthcare providers may program or configure dataprocessing module 1600 to provide certain compliance with analytemonitoring regimen, so that frequent determination of analyte levels ismaintained or performed by the user.

In certain embodiments, when a programmed or programmable alarmcondition is detected (for example, a detected glucose level monitoredby analyte sensor 14 that is outside a predetermined acceptable rangeindicating a physiological condition) which requires attention orintervention for medical treatment or analysis (for example, ahypoglycemic condition, a hyperglycemic condition, an impendinghyperglycemic condition or an impending hypoglycemic condition), the oneor more output indications may be generated by the control logic orprocessor of the on body electronics 1100 and output to the user on auser interface of on body electronics 1100 so that corrective action maybe timely taken. In addition to or alternatively, if display device 1200is within communication range, the output indications or alarm data maybe communicated to display device 1200 whose processor, upon detectionof the alarm data reception, controls the display 1220 to output one ormore notification.

In certain embodiments, control logic or microprocessors of on bodyelectronics 1100 include software programs to determine future oranticipated analyte levels based on information obtained from analytesensor 14, e.g., the current analyte level, the rate of change of theanalyte level, the acceleration of the analyte level change, and/oranalyte trend information determined based on stored monitored analytedata providing a historical trend or direction of analyte levelfluctuation as function time during monitored time period. Predictivealarm parameters may be programmed or programmable in display device1200, or the on body electronics 1100, or both, and output to the userin advance of anticipating the user's analyte level reaching the futurelevel. This provides the user an opportunity to take timely correctiveaction.

Information, such as variation or fluctuation of the monitored analytelevel as a function of time over the monitored time period providinganalyte trend information, for example, may be determined by one or morecontrol logic or microprocessors of display device 1200, data processingmodule 1600, and/or remote terminal 1700, and/or on body electronics1100. Such information may be displayed as, for example, a graph (suchas a line graph) to indicate to the user the current and/or historicaland/or and predicted future analyte levels as measured and predicted bythe analyte monitoring system 1000. Such information may also bedisplayed as directional arrows (for example, see trend or directionalarrow display 1310) or other icon(s), e.g., the position of which on thescreen relative to a reference point indicated whether the analyte levelis increasing or decreasing as well as the acceleration or decelerationof the increase or decrease in analyte level. This information may beutilized by the user to determine any necessary corrective actions toensure the analyte level remains within an acceptable and/or clinicallysafe range. Other visual indicators, including colors, flashing, fading,etc., as well as audio indicators including a change in pitch, volume,or tone of an audio output and/or vibratory or other tactile indicatorsmay also be incorporated into the display of trend data as means ofnotifying the user of the current level and/or direction and/or rate ofchange of the monitored analyte level. For example, based on adetermined rate of glucose change, programmed clinically significantglucose threshold levels (e.g., hyperglycemic and/or hypoglycemiclevels), and current analyte level derived by an in vivo analyte sensor,the system 1000 may include an algorithm stored on computer readablemedium to determine the time it will take to reach a clinicallysignificant level and will output notification in advance of reachingthe clinically significant level, e.g., 30 minutes before a clinicallysignificant level is anticipated, and/or 20 minutes, and/or 10 minutes,and/or 5 minutes, and/or 3 minutes, and/or 1 minute, and so on, withoutputs increasing in intensity or the like.

Referring again back to FIG. 1, in certain embodiments, softwarealgorithm(s) for execution by data processing module 1600 may be storedin an external memory device such as an SD card, microSD card, compactflash card, XD card, Memory Stick card, Memory Stick Duo card, or USBmemory stick/device including executable programs stored in such devicesfor execution upon connection to the respective one or more of the onbody electronics 1100, remote terminal 1700 or display device 1200. In afurther aspect, software algorithms for execution by data processingmodule 1600 may be provided to a communication device such as a mobiletelephone including, for example, WiFi or Internet enabled smart phonesor personal digital assistants (PDAs) as a downloadable application forexecution by the downloading communication device.

Examples of smart phones include Windows®, Android™, iPhone® operatingsystem, Palm® WebOS™, Blackberry® operating system, or Symbian®operating system based mobile telephones with data network connectivityfunctionality for data communication over an internet connection and/ora local area network (LAN). PDAs as described above include, forexample, portable electronic devices including one or moremicroprocessors and data communication capability with a user interface(e.g., display/output unit and/or input unit, and configured forperforming data processing, data upload/download over the internet, forexample. In such embodiments, remote terminal 1700 may be configured toprovide the executable application software to the one or more of thecommunication devices described above when communication between theremote terminal 1700 and the devices are established.

In still further embodiments, executable software applications may beprovided over-the-air (OTA) as an OTA download such that wiredconnection to remote terminal 1700 is not necessary. For example,executable applications may be automatically downloaded as softwaredownload to the communication device, and depending upon theconfiguration of the communication device, installed on the device foruse automatically, or based on user confirmation or acknowledgement onthe communication device to execute the installation of the application.The OTA download and installation of software may include softwareapplications and/or routines that are updates or upgrades to theexisting functions or features of data processing module 1600 and/ordisplay device 1200.

Referring back to remote terminal 1700 of FIG. 1, in certainembodiments, new software and/or software updates such as softwarepatches or fixes, firmware updates or software driver upgrades, amongothers, for display device 1200 and/or on body electronics 1100 and/ordata processing module 1600 may be provided by remote terminal 1700 whencommunication between the remote terminal 1700 and display device 1200and/or data processing module 1600 is established. For example, softwareupgrades, executable programming changes or modification for on bodyelectronics 1100 may be received from remote terminal 1700 by one ormore of display device 1200 or data processing module 1600, andthereafter, provided to on body electronics 1100 to update its softwareor programmable functions. For example, in certain embodiments, softwarereceived and installed in on body electronics 1100 may include softwarebug fixes, modification to the previously stalled software parameters(modification to analyte related data storage time interval, resettingor adjusting time base or information of on body electronics 1100,modification to the transmitted data type, data transmission sequence,or data storage time period, among others). Additional detailsdescribing field upgradability of software of portable electronicdevices, and data processing are provided in U.S. application Ser. Nos.12/698,124, 12/794,721, 12/699,653, and 12/699,844, and U.S. ProvisionalApplication Nos. 61/359,265, and 61/325,155 the disclosures of which areincorporated by reference herein for all purposes.

The Sensor

The analyte sensor 14 of the analyte measurement system 100 may be usedto monitor levels of a wide variety of analytes. Analytes that may bemonitored include, for example, acetylcholine, amylase, bilirubin,cholesterol, chorionic gonadotropin, creatine kinase (e.g., CK-MB),creatine, DNA, fructosamine, glucose, glutamine, growth hormones,hormones, ketones, lactate, peroxide, prostate-specific antigen,prothrombin, RNA, thyroid-stimulating hormone, and troponin. Theconcentration of drugs, such as, for example, antibiotics (e.g.,gentamicin, vancomycin, and the like), digitoxin, digoxin, drugs ofabuse, theophylline, and warfarin, may also be monitored. One or moreanalyte may be monitored by a given sensor. In those embodiments thatmonitor more than one analyte, the analytes may be monitored at the sameor different times, which may use the same on body electronics (e.g.,simultaneously) or with different on body electronics.

In one embodiment of the present disclosure, sensor 14 is physicallypositioned in or on the body of a user whose analyte level is beingmonitored. Sensor 14 may be configured to continuously sample theanalyte level of the user and convert the sampled analyte level, e.g.,glucose concentration into a corresponding data signal, e.g., a currentor voltage, for input into on body electronics. Alternatively, sensor 14may be configured to sample analyte levels on demand. The on bodyelectronics may amplify, filter, average, and/or otherwise processsignal provided by the sensor.

An embodiment of the sensor 14 is illustrated in FIG. 2. It isunderstood that the inserters described herein can be used with othermedical devices. The shape(s) described herein are exemplary only. Othersensor shapes are contemplated. In some embodiments, sensor 14 includesa substrate which is a dielectric, e.g., a polymer or plastic material,such as polyester or polyamide. In this embodiment, the sensor isconstructed so that a portion is positionable beneath skin and a portionis above skin. Accordingly, sensor 14 includes an insertion or internalportion 30 and an external or electrical contact portion 32. In someembodiments, the contact portion 32 includes several conductive contacts36, 38, and 40 (herein shown as three contacts) for connection to otherelectronics, e.g., at the on body electronics 1100. (See FIG. 1.) Thecontacts provided in this embodiment are for a working electrode, areference electrode, and a counter electrode. In some embodiments, twoor more working electrodes are provided. The operative portions of theseelectrodes, that is, working electrode, reference electrode, and counterelectrode (not individually shown), are provided at the insertionportion, e.g., at the distal end of insertion portion 30, e.g., portion34. In some embodiments, one or more electrodes may be external to thebody, e.g., an external counter electrode. The contact and operativeportions of the electrodes are connected by circuit traces 42, 44, and46 running on the surface of the substrate. In some embodiments, thetraces are provided in channels, or may be embedded within thesubstrate, or may traverse different sides of the substrate. Theconductive contacts, conductive traces, and electrodes are fabricatedfrom conductive material, such as platinum, palladium, gold, carbon, orthe like. More than one material may be used for a given sensor. Furtherdetails of sensors are described, e.g., in U.S. Pat. Nos. 6,175,572 and6,103,033, which are incorporated by reference herein for all purposes.

Sensor 14 may include a proximal retention portion 48. The insertionportion 30 and the proximal retention portion 48 are sized andconfigured to be positioned with a sharp for installation into the skinof a subject, as described herein. In use, the sensor 14 may beconfigured to bend (e.g., along the line B) and therefore be positionedin two substantially perpendicular, intersecting planes. Such bendingmay occur prior to or during coupling to the on body electronics asdescribed below. (See FIG. 17).

Portions 48 and 52 provide a path for electrical connections, e.g., theconductive traces, between the proximal and distal portions of thesensor. Sensor 14 is further provided with a notch or cut-out 54. Suchconfiguration facilitates the sensor 14 to bend (e.g., along the lineindicated by line B) such that retention portion 48 remains upright andtherefore be positioned in two substantially perpendicular, intersectingplanes, as illustrated in FIG. 3. As will be described below, the sensortab 50 can be encased in the on body housing 122 to aid in securing andpositioning the sensor 14. Proximal retention portion 48 maintains itslongitudinal alignment with insertion portion 30 for positioning withinan insertion sharp.

Embodiments of analyte sensors have been described herein to operateelectrochemically, through an arrangement of electrodes having chemicalsensing layers applied thereto, by generating an electrical currentproportional to the volume of a redox reaction of the analyte (andindicative of analyte concentration), catalyzed by an analyte-specificoxidizing enzyme. Embodiments exist in which the number of electrodesprovided to bring about and detect the level of these reactions is two,three, or a greater number. However, other types of sensors may beemployed as described herein.

A portion of sensor 14 may be situated above the surface of the skin,with a distal portion 30 penetrating through the skin and into thesubcutaneous space in contact with the user's biofluid, such as ISF.Further details regarding the electrochemistry of sensor 14 is providedin U.S. Pat. Nos. 5,264,104; 5,356,786; 5,262,035; 5,320,725; and6,990,366, each of which is incorporated by reference herein for allpurposes.

In some embodiments, the sensor is implantable into a subject's body fora usage period (e.g., a minute or more, at least one day or more, aboutone to about 30 days or even longer, about three to about fourteen days,about three to about seven days, or in some embodiments, longer periodsof up to several weeks) to contact and monitor an analyte present in abiological fluid. In this regard, the sensor can be disposed in asubject at a variety of sites (e.g., abdomen, upper arm, thigh, etc.),including intramuscularly, transcutaneously, intravascularly, or in abody cavity.

In some embodiments, sensor 14 is employed by insertion and/orimplantation into a user's body for some usage period. In suchembodiments, the substrate may be formed from a relatively flexiblematerial.

While the embodiments illustrated in FIGS. 2-3 have three electrodes,other embodiments can include a fewer or greater number of electrodes.For example, a two-electrode sensor can be utilized. The sensor 14 maybe externally-powered and allow a current to pass which is proportionalto the amount of analyte present. Alternatively, the sensor 14 itselfmay act as a current source in some embodiments. In some two-electrodeembodiments, the sensor may be self-biasing and there may be no need fora reference electrode. An exemplary self-powered, two-electrode sensoris described in U.S. patent application Ser. No. 12/393,921, filed Feb.26, 2009, and entitled “Self-Powered Analyte Sensor,” which is herebyincorporated by reference herein for all purposes. The level of currentprovided by a self-powered sensor may be low, for example, on the orderof nanoamperes, in certain embodiments.

Insertion Assembly

Insertion assemblies are provided, which are used to install a medicaldevice to the subject. In some embodiments, an insertion assemblyincludes an inserter and the medical device itself. The inserter can beconfigured to insert various medical devices into the subject, such asfor example, an analyte sensor, an infusion set, or a cannula. In someembodiments, the inserter can be configured to install a combination ofsuch devices, e.g., a combined sensor/infusion set, etc., at the same ordifferent times or locations. For example, in certain embodiments agiven inserter can be configured to install a first device and a seconddevice at different times. In this regard, the inserter can be reusable.For example, an inserter may be modifiable to be used with more than onemedical device, to include more than one type of medical device, e.g.,by attaching an adapter and/or removing detaching a portion of aninserter. The inserter can install the medical device in, under, orthrough the skin of the subject, or place the medical device on thesurface of the skin. The medical device can include features orstructures, e.g., barbs, tabs, adhesive, etc., to maintain the device inposition with respect to the skin after insertion. The inserter devicemay also be used as a lancet, e.g., to pierce the skin without insertingor installing a medical device.

In some embodiments, an insertion assembly includes an inserter, ananalyte sensor, and a power supply. The power supply may be applied tothe patient, e.g., to the surface of the skin, simultaneously with theanalyte sensor by the inserter. In other embodiments, the battery isinstalled after or before installation of the analyte sensor. In suchcase the power supply may be applied by the inserter or separately. Thepower supply may be used to provide a current or a potential to thesensor and/or to provide power for communication of one or more signalsto the monitor unit.

In some embodiments, an insertion assembly includes an inserter, amedical device such as an analyte sensor, and on body electronics. Theon body electronics may be deployed and/or installed simultaneously withthe analyte sensor by the inserter. In other embodiments, the on bodyelectronics are installed after or before installation of the analytesensor. For example, the analyte sensor may be installed by theinserter, and the on body electronics may be subsequently installed.

In some embodiments, the on body electronics provide a voltage orcurrent to the analyte sensor. In some embodiments, the on bodyelectronics process signals provided by the analyte sensor. In furtherembodiments, the on body electronics may include communicationsfunctionality for providing signal relating to signal provided by theanalyte sensor to a further component, such as, e.g., a monitor unit, acomputer, or other component. In some embodiments, communicationscircuitry, such as an RFID antenna, is provided. The power supply may beused to power some or all of these functions. In some embodiments, poweris provided from the monitor unit, e.g., via inductive coupling.

An inserter can include a plurality of different components. Forexample, an inserter may include one or more components for advancing asharp towards the skin of the subject. The sensor and on bodyelectronics may be supported by a support structure, such as a carriage.A driver may be provided for advancing the sharp and/or the analytesensor/support structure towards the skin of the patient. In someembodiments, the actuator is directly or indirectly coupled to the sharpand/or support structure, such that manual force applied by the user tothe actuator is transferred to the sharp and/or support structure. Insome embodiments, the applied force drives the sharp and/or supportstructure between a retracted position (disposed within the insertiondevice) and an advanced position (disposed towards the skin of thepatient). In some embodiments, the sensor and on body electronics ismaintained in a refracted position prior to installation by contactingprojections extending inwardly from a recess in the inserter. Inaccordance with this embodiment, the sensor and on body electronics aretemporarily maintained operatively between the support structure and theprojections disposed on the interior wall of the sheath.

An inserter can also include one or more components for retracting thesharp, while allowing the analyte sensor and optional on bodyelectronics to remain on the subject. The components for retracting thesharp can include a refractor. It is understood that the retractor andthe actuator may be the same structure or include some commoncomponents. In some embodiments, the refractor is directly or indirectlycoupled to the sharp such that the manual force applied by the user istransferred from the retractor to the sharp to retract the sharp fromthe skin. In other embodiments, a drive assembly may be provided toretract the sharp. For example, the drive assembly may include a spring,motor, hydraulic piston, etc., to retract the sharp away from the skinof the subject. The drive assembly may also include a linear drivecomponent.

In some embodiments, the retractor withdraws the sharp upon actuation bythe user. In such cases, the user actuates the retractor when it isdesired to withdraw the sharp. For example, the retractor may include arelease switch. Upon activation of the release switch, the driveassembly, e.g., the spring or other driver, retracts the sharp from theskin. In other embodiments, the retractor and the actuator includecommon components. After activating the actuator to advance the sharpand the analyte sensor, the user releases the actuator, which allows thedrive assembly to withdraw the sharp from the skin.

In some embodiments, the retractor withdraws the sharp without furtheruser interaction after actuation of insertion. For example, the insertermay include features or components which automatically retract the sharpupon advancement of the sharp and support structure by a predeterminedamount. Inserter devices, in which no further action by the user isrequired to initiate withdrawal of the sharp after insertion, arereferred to herein as having “automatic” withdrawal of the sharp.

Inserter Devices

An inserter 200 in accordance with an exemplary embodiment isillustrated in FIG. 4. Inserter 200 includes a housing 202 and aremovable distal cap 204 for maintaining a sterile environment for themedical device and sharp housed therein. In some embodiments, inserter200 has a maximum diameter, of about 30 mm to about 60 mm, e.g., about40 mm, about 43 mm, about 43.5 mm, about 50.5 mm, about 54.5 mm, etc. Insome embodiments, inserter 200 has a maximum height of about 40 mm toabout 80 mm, e.g., about 44 mm, about 46 mm, about 50 mm, about 53 mm,about 67 mm, about 71 mm, etc. In some embodiments, inserter 200 has avolume of about 35 cm³ to about 110 cm³, e.g., about 40 cm³, about 41cm³, about 50 cm³, about 60 cm³, about 61 cm³, about 62 cm³, about 69cm³, about 70 cm³, about 79 cm³, about 90 cm³, about 106 cm³, etc. Inthe case of inserter 200, the dimensions are defined with respect to thehousing 202.

Housing 202 and distal cap 204 may be fabricated from any suitablematerials such as metal, plastic, etc. In some embodiments cap 204 maybe fabricated from a polymer or plastic material. Also provided is aremovable proximal cover 206, which, among other things, preventsaccidental deployment of the inserter 200 and maintains a sterileenvironment. In some embodiments, proximal cover 206 is a sheet ofmaterial such as a foil sheet or the like secured to the upper surfaceof housing 202 using an adhesive, and may include a tab 208 to assistremoval of the cover 206. Proximal cover 206 may also be a plastic sheetor member that forms a seal with housing 202. In some embodiments,proximal cover 206 may include a pull tab or a perforated section foreasy removal.

As illustrated in FIG. 5, proximal cover 206 and distal cap 204 areshown removed from inserter 200. Distal cap 204 is secured to housing202, e.g., by use of threads 210. In some embodiments, distal cap 204 issecured by a friction fit, snap fit, a bayonet mount, an adhesive, etc.The distal portion of cap 204 may include a recess for retaining adesiccant therein. In some embodiments, a silica gel or molecular sievesmay be used. Such material can be in granular form (pellets) or pressedinto tablets, or otherwise. In some embodiments, silica gel tablets areused. Embodiments may include desiccant and/or packaging as described inU.S. patent application Ser. No. 12/714,439, which is incorporated byreference herein for all purposes. Cap 204 may be provided with one ormore apertures, which allows for passage of air to the desiccant toremove moisture from the interior of the inserter 200.

Housing 202 includes a distal portion 212 for placement on the skin of asubject. Inserter 200 includes an actuator 214 to advance a medicaldevice into the skin of the subject. In some embodiments, actuator 214is disposed within an opening 216 in housing 202 and can belongitudinally moveable within housing 202.

The distal portion of inserter 200 is illustrated in FIG. 6. In someembodiments, an adhesive pad 218, having adhesive material 218 on bothfaces, is provided across the distal portion 212 of the housing 202. Acentral aperture 220 may be provided in adhesive pad 218. As will bedescribed in greater detail herein, inserter 200 supports a medicaldevice, such as on body housing 122 (not shown) and a sharp 224. In someembodiments, on body housing 122, includes an analyte sensor 14. Duringinsertion, sharp 224 passes through aperture 220 and into the skin ofthe subject carrying at least the sensor 14 with it.

FIG. 7 illustrates inserter 200 in cross-section, in an initialconfiguration prior to use, after removal of the distal cap 204.Actuator 214 may be cylindrical in shape (or other shape as appropriate)and, including an upper contact surface 226, capable of being depressedby a user and/or a mechanism, as described herein. Actuator 214 mayfurther include side walls 228 extending downwardly from upper surface226, and which engage or otherwise contact the upper surface of carriage230. Carriage 230 provides a support for holding the medical device,such as on body housing 122, prior to and during installation. In someembodiments, carriage 230 includes a distal portion 232, which may beconfigured to form a substantially concave recess 232 a as shown in thisembodiment, for supporting the medical device therein. In someembodiments, the on body housing 122 is supported within the recess 232a of carriage 230 in a snap-fit or other relationship. In someembodiments, carriage 230 does not include a recess. In suchembodiments, carriage may include one or more projections which contactand/or advance the on body housing 122. (See, e.g., FIGS. 122, 135-136herein.)

In FIG. 8 the longitudinal axis L of the inserter 200 is illustrated.Extending distally from the upper surface 226 of actuator 214 andsubstantially parallel to the longitudinal axis is a support member 234,which may have an elongated configuration. Support member 234 supportsneedle hub 236, from which sharp 224 extends longitudinally within theinserter 200. In some embodiments, the sharp 224 is supported at anoblique angle, e.g., between about 0° and 90° with respect to the skinsurface. Needle hub 236 can be secured to support member 234 via aninterlocking O-ring configuration, adhesive, or other techniques knownin the art. Support member 234 can be omitted and needle hub 236 can besecured to the actuator 214 directly in some embodiments, e.g., bymanufacturing needle hub 236 as a single component with actuator 214 orby otherwise adhering needle hub 236 to actuator 214.

In some embodiments, sharp 224 is a solid needle, for example, ifinserter 200 is used to insert a cannula. In some embodiments, sharp 224is provided with a substantially cylindrical configuration defining aninterior bore, e.g., a rigid cylindrical member or a hypodermic-styleneedle. Sharp 224 may also be provided with an elongated longitudinalopening or gap in the wall of the sharp 224 (see, sharp 224 in FIGS.11-18). In some embodiments, sharp 224 is fabricated from a sheet ofmetal, and folded into a substantially “V” or “U” or “C” configurationin cross-section to define the longitudinal recess.

Needle hub 236 is further illustrated in FIGS. 9-10. Needle hub 236supports sharp 224, having a sharpened distal portion 260. In someembodiments, as discussed herein, a longitudinal wall opening or gap 262is provided in at least a portion of the wall of the sharp 224. Thelength N of the gap 262 is selected to be commensurate with the lengthof the insertion portion 30 through to the proximal retention portion 48of the sensor 14 where the bend at line B occurs (See FIGS. 2-3), and incertain embodiments may be about 3 mm to about 50 mm, e.g., about 5 mm,or about 10 mm, or about 15 mm, or about 20 mm. The length L of thesharp 224 may be about 3 mm to about 50 mm, e.g., 5 mm or more, or about10 mm, or about 20 mm, or about 30 mm, or about 50 mm, and is selectedbased upon the length of the insertion portion 30 of a sensor and thedesired depth of the insertion portion 30 of the sensor 14. In someembodiments, the distance or spacing between the two edges of the gap isabout 0.2 mm to about 0.5 mm, e.g., about 0.22 mm, about 0.25 mm, etc.(See, spacing 257 in FIG. 11).

The distal portion 260 of sharp 224 is illustrated in greater detail inFIGS. 11-13. As illustrated in FIG. 11, sharp 224 has a substantially“C”- or “U”-shaped profile in this embodiment, but may have otherconfigurations, e.g., substantially “V”-shaped. A longitudinal gap 262is provided in the wall of the sharp 224. FIG. 12 illustrates distalportion 260 is provided with an angled tip. In some embodiments, theangled tip may be provided with a first angled tip portion 264 and asecond steep-angled tip portion 266. The exemplary configuration, whichincludes multiple edges and faces, provides a sharp point to reducepenetration force, trauma, and bleeding for the subject. The distalsection of the sensor body has a width sized to fit within the gap 262of the insertion sharp 224 having a diameter less than about 20 to about26 gauge, e.g., 21 gauge to about 25 gauge, where in certain embodimentsthe sharp is 21 gauge or 23 gauge or 25 gauge. Such sharp may be usedwith a sensor having a width or diameter—at least the portion that iscarried by the sharp—of about 0.20 mm to about 0.80 mm, e.g., about 0.25mm to about 0.60 mm, where in some embodiments the width or diameter ofat least a portion of a sensor is 0.27 mm or 0.33 mm or 0.58 mm. In someembodiments, sharp 224 is fabricated from a sheet of metal and foldedinto a substantially “V” or “U” or “C” configuration in cross-section.

Various technologies can be used to manufacture a folded sheet of metalto form sharp 224. For example, etched-sheet metal technology can beused to form the sharp 224. In this manner, the sharp can be formedhaving a very sharp edge so that penetration through the skin duringinsertion is less painful. In other embodiments, a progressive dietechnology may be utilized to form a complex sheet-metal shape that hasa sharp edge as depicted in FIG. 14. In some embodiments, the sharp 224can be molded with a plastic cap so that the sharp can be handled duringthe inserter assembly process. Further, the die cut sharp may be moldedwith plastic to reinforce the “V,” “U,” or “C” shaped sheet metalconfiguration. In some embodiments, a “U” shaped cross-section can beprovided with having flat, rather than curved walls. The “U” shapedconfiguration provides the advantage that they can more securely andclosely hold the sensor. Also, the “U” shaped configuration provides theadvantage that it has a reduced cross-section when compared with acomparable circular cross section. Further details of the tip of sharp224 are illustrated in FIGS. 14A-C. As illustrated in FIGS. 14A-B, a topview of the sharp 224 is shown. This represents a flat portion of thesharp, e.g., the bottom of the “U” configuration. A tip is formed byfirst distal edges 263 closest to the distal tip and second distal edges265 between the first distal edges 263 and the substantially parallelside walls 269. In some embodiments, the first distal edges 263 form an“included tip” angle of about 15 degrees, about 30 degrees, or about 60degrees. Such angle is symmetrical, that is, equal angles from thelongitudinal axis of the sharp 224. The second distal edges 265 providea somewhat less acute angle than the first distal edges 263. In someembodiments, the “lead in” angle may be about 20 degrees, about 45degrees, or about 65 degrees. By having a tip defined by two angles, afirst, smaller “included angle” and a second, larger “lead in angle,”allows the tip to meet several objectives. First, the small includedangle allows the tip to pierce the skin with less trauma. Second, bybroadening out to a larger angle, the overall length of the tip isreduced and strength of the tip is increased. FIG. 14C illustrates aside view of the sharp 224 and illustrates the side walls 269. Anadditional angle, i.e., the “lead-out” angle is provided by the risingedge 267 of the sharp. The edge 267 provides the ability to separate thetissue to allow placement of the sensor 14. In other embodiments, alaser-cut sharp can be formed. In this manner, the laser can be used toform the wall opening or gap 262 and first-angled tip portion 264 and asecond, steep-angled tip portion 266.

In another embodiment, sharp 224 may be formed from a standardhypodermic needle utilizing the method depicted in FIG. 15. First, thehypodermic needle (having a circular cross-section) is cut to thedesired length for sharp 224. Next, the hypodermic needle is compressedso that its cross-section is permanently deformed from a circular shapeto an oval shape. The tip of the hypodermic needle is then ground to abevel to produce a sharp point to reduce the required penetration force,as previously discussed. Finally, the top section of the needle isremoved by appropriate techniques (e.g., grinding, electropolish, etc.).The resulting sharp 224 has a “U”-shaped configuration and providesample space for the insertion of sensor 14. In some embodiments, thetip-grinding step and the compression step may be carried out inreversed order.

Due to the compression step, a user may initially start with a largerdiameter hypodermic needle so that the finished sharp 224 will havesimilar dimensions to the previously described sharps.

FIGS. 16-18 illustrate the position of on body housing 122 with respectto the needle hub 236 and sharp 224. The on body housing 122 can beconfigured to hold at least a portion of sensor 14 and on bodyelectronics 1100 (also referred to herein as electronics 80). Asillustrated in FIG. 16, the sharp 224 extends through an aperture 168 inthe on body housing 122. Thus, in some embodiments, the sharp 224 isuncoupled to on body housing 122. The distal portion of sensor 14 ispositioned within the sharp 224. As further illustrated in FIG. 17, onbody electronics 1100 and sensor hub 123 are positioned within on bodyhousing 122. Sensor 14 may include an optional positioning structure, orslit 127, which receives a positioning member, such as tab 129 of sensorhub 123. A power supply 82, such as a battery, e.g., a single usedisposable battery, or rechargeable battery, is optionally provided.

FIG. 17A illustrates a detail of sensor hub 123, which includes anaperture 190 through which sharp 224 and sensor 14 are configured topass through. In some embodiments, aperture 190 is provided with anadditional side channel 192 continuous with the aperture 190. Sidechannel 192 is positioned in the location in which the pointed tip 260of the sharp 224 would first pass through the aperture. Ideally, the tip260 passes through the aperture without contacting the sensor hub 123.However, if there is any misalignment, the tip 260 makes contact withthe sensor hub 123 and may be damaged and/or it may become jammed orotherwise unable to pass through the aperture. The side channel 192provides additional clearance for the tip 260 to pass through theaperture undamaged.

FIG. 18 illustrates in cross-section the orientation of the on bodyhousing 122 with respect to the sharp 224 of inserter 200. As discussedherein, sensor 14 is disposed in a substantially bent configuration insome embodiments, such that a portion of the sensor, e.g., the insertionportion 30 and the proximal retention portion 48, are substantiallyvertical (e.g., substantially aligned with the longitudinal axis of theinserter 200 and substantially perpendicular to the skin surface) andthe contact portion 32 (shown in profile) is oriented in a substantiallyhorizontal configuration, and in electrical contact with on bodyelectronics 1100. The sensor tab 50 can be encapsulated in the plasticof the on body housing 122 and secured in place. The notch 56 providesfurther stability to the sensor 14, e.g., by allowing the sensor tab 50to be encased by the material of the on body housing 122, and furtherprovides a means for vertically orienting the sensor 14 during mounting,e.g., by allowing vertical positioning of the notch 56 with respect theon body housing 122.

The sensor 14, mounted with the on body housing 122, can be disposedwithin a recess of the carriage 230 such as a concave recess in thecarriage 230. Alternatively, the sensor 14, mounted with the on bodyhousing 122 can be disposed between the support structure and one ormore projections extending from the wall of the sheath 242 (not shown).In yet another alternative, the sensor 14 mounted with the on bodyhousing 122 can be held in position by a releasable friction fitcoupling to the sharp 224. In this manner, the carriage need not have arecess within which the sensor mounted with the on body housing isdisposed. In the initial configuration of the inserter 200 (see, e.g.,FIG. 7) the sharp 224 extends through a longitudinal aperture 168 formedin a carriage 230. In some embodiments, the aperture 168 isappropriately sized, such that neither the sharp 224 nor needle hub 236is in contact with the carriage 230. Accordingly, the needle hub 236(and sharp 224) on the one hand, and the carriage 230 and the on bodyhousing 122, on the other hand, move simultaneously but independentlyfrom one another. In other embodiments, a friction fit may be providedbetween the aperture and the sharp.

The insertion portion 30 and proximal retention portion 48 of the sensor14 are disposed within a longitudinal bore 162 within the sharp 224(See, e.g., FIG. 7). The proximal retention portion 48 is disposedwithin the longitudinal bore of the sharp 224 and provides additionalstability to the mounting of the sensor 14 within the sharp 224. Thelongitudinal wall gap or opening 262 of sharp 224 is aligned with thesensor 14, such that the tab 50 and the contact portion 32 extendlaterally outward from the sharp 224.

In some embodiments, a resilient member 70 may be included to providefrictional contact with the sharp 224 and/or the sensor 14. Suchfrictional contact provides additional stability between the on bodyhousing 122 and sharp 224, as depicted in FIGS. 19-21. In someembodiments, resilient member 70 may be formed as a spherical, ovoid,cylindrical, cube-shaped member, etc. Resilient member 70 may be formedfrom any elastomeric material, e.g., molded plastic components, rubber,nitrile, viton, urethane, etc.

In some embodiments, resilient member 70 is press-fit into a recess,such as an eccentric bore 72 located in on body housing 122 (FIG. 21).When sharp 224 is inserted within an aperture in the on body housing122, the resilient member 70 exerts a pressure on sharp 224 and sensor14 to hold them firmly in groove 74. In some embodiments, groove 74 is aV-shape. Alternatively, groove 74 may be U-shaped depending on theconfiguration of sensor 14 and sharp 224. In some embodiments, resilientmember 70 is provided with a flattened or recessed surface which abutssharp 224.

The sensor 14, mounted with the on body housing 122, is carried by thecarriage, e.g., disposed within the concave recess 232 a in the carriage230, as described hereinabove (see, e.g., FIGS. 16-21). In the initialconfiguration of the inserter 200 (see, e.g., FIG. 7), the sharp 224extends through a longitudinal aperture formed in the carriage 230. Insome embodiments, the aperture is appropriately sized, such that neitherthe sharp 224 nor needle hub 236 is in contact with the carriage 230. Inother words, in some embodiments a clearance may be provided between thesurfaces of the carriage and the sharp and needle hub. In some cases,sharp 224 is capable of substantial lateral movement or “play” withrespect to aperture. Accordingly, the needle hub 236 (and sharp 224) onthe one hand, and the carriage 230 and the on body housing 122, on theother hand, can move simultaneously but independently from one another.

Referring back to FIG. 17, the insertion portion 30 and proximalretention portion 48 of the sensor 14 are disposed within a longitudinalbore of the sharp 224. The proximal retention portion 48 is disposedwithin the longitudinal bore 225 of the sharp 224 and providesadditional stability to the disposition of the sensor 14 withinlongitudinal bore 225 of the sharp 224. The longitudinal wall gap ofsharp 224 is aligned with the sensor 14, such that the tab 50 and thecontact portion 32 extend laterally outward from the sharp 224.

With continued reference to FIG. 7, an optional sheath 242 is positionedwithin housing 202, having an annular configuration and including acircumferential recess 244 in which a retraction spring 246 ispositioned. The distal portion of spring 246 contacts a spring retentionportion 248 in sheath 242. The proximal portion of spring 246 contactsone or more tabs 250 extending laterally outwardly from actuator 214. Inthe initial configuration, the spring 246 may be in a semi-compressedstate, i.e., not fully compressed, nor fully extended. It is understoodthat sheath 242 may be omitted from inserter 200, and a recess, such asrecess 244, provided within housing 202. Similarly, recess 244 may beomitted entirely, and spring 246 or other actuator may be disposedbetween stops in housing 202.

Depression of the actuator 214 causes distal longitudinal movement ofthe carriage 230 and sharp 224, from a proximal position (spaced apartfrom the skin of the subject) to a distal position (closer to the skinof the subject). During such downward, distal movement, spring 246 isfurther compressed between spring retention portion 248 and flanges 270.

As illustrated in FIG. 8, depression of the contact surface 226 movesthe actuator side walls 228 and the tabs 250 downwardly distally againstthe bias of spring 246. Contact of the side wall 228 of the actuator 214with the upper surface of the carriage 230 during depression of theactuator 214 imposes a downward force and consequential distal movementof the carriage 230. As the sharp 224 is urged distally, it carries thesensor insertion portion 30 into the subcutaneous portion of thesubject's skin S.

As illustrated in FIG. 7, flanges 270 are disposed in the inner wall ofsheath 242. When carriage 230 reaches a distal position, as shown inFIG. 8, the flanges 270 engage the proximal (upper) surface of thecarriage 230, and thereby inhibit proximal movement of the carriage 230(see also FIG. 24). The distal (lower) surface of the on body housing122 engages the upper surface of adhesive pad 218, thereby becomingadhered to the skin surface S of the subject. As the flanges 270 engagethe carriage 230, the flanges 270 also engage fingers 274 disposed onthe proximal face of the carriage 230. Fingers 274 are pivoted inwardsby flanges 270. Such pivoting of fingers 274 causes fingers 274 tobecome disengaged from retention tab 250 on actuator 214. Spring 246 isthereby permitted to decompress and expand, and thereby provide anupward force on actuator 214. If the user or some apparatus provides nodownward force, or minimal downward force to overcome the bias of spring246, the actuator 214, along with needle hub 236 and sharp 224 moveproximally, withdrawing the sharp 224 from the skin S of the subject.

As shown in FIGS. 22 and 23, the actuator 214 and coupled sharp 224advances to a more proximal position than at the initial configurationillustrated in FIGS. 5 and 7 due to the decoupling of actuator 214 fromcarrier. Thus the sharp 224 retracts from a distal position to aproximal position after installation of the on body housing 122 andinsertion of at least a portion of the sensor.

A further embodiment of an inserter is illustrated in FIGS. 25-39 anddesignated inserter 300. In some embodiments, inserter 300 has a maximumdiameter of about 30 mm to about 60 mm, e.g., about 40 mm, about 43 mm,about 43.5 mm, about 50.5 mm, about 54.5 mm, etc. In some embodiments,inserter 300 has a maximum height of about 40 mm to about 80 mm, e.g.,about 44 mm, about 46 mm, about 50 mm, about 53 mm, about 67 mm, about71 mm, etc. Such height is defined by the total length of the housing302 and the sheath 342. In some embodiments, inserter 300 has a volumeof about 35 cm³ to about 110 cm³, e.g., about 40 cm³, about 41 cm³,about 50 cm³, about 60 cm³, about 61 cm³, about 62 cm³, about 69 cm³,about 70 cm³, about 79 cm³, about 90 cm³, about 106 cm³, etc. Suchdimensions are defined by the total length of the housing 302 and thesheath 342.

As illustrated in FIGS. 25-26, inserter 300 in certain embodimentsincludes, e.g., a handle 302, a sheath 342, and a removable distal cap304 for maintaining a sterile environment for the medical device andsharp housed therein. FIG. 26 illustrates that distal cap 304 is removedfrom handle 302. Distal cap 304 is secured to handle 302 by one of anumber of securement means, e.g., by use of threads 310. Sheath 342defines a distal surface 312 for placement on the skin of a subject.Inserter 300 may be utilized to advance a medical device into the skinof the subject. In some embodiments, handle 302 is advanced relative tosheath 342 in order to advance the medical device into the skin of thepatient.

The components of inserter 300 in certain embodiments are illustrated inFIGS. 27-32. As illustrated in FIG. 27, handle 302 may include threads310 for attachment of cap 304 via threads 311 (as illustrated in FIG.29). It is understood that other securement techniques, such as asnap-fit or friction-fit may be used to secure cap 304. Cap 304 mayinclude a receptacle 325 for positioning of the sharp 324. Sheath 342,as illustrated in FIG. 28, includes longitudinal notches 382.

Projections 386 on carriage 330, as illustrated in FIG. 30, areconfigured to engage sheath to secure carriage 330 within the inserter300, thereby preventing release of the carriage 330 from the inserter300. When the projections 386 of carrier reach the bottom of the notches382, such bottom surface acts as the retention portion that prevents thecarriage 330 from falling out of the inserter 300. Projections 375engage with the triangular latch features 370 of the sheath 342 asillustrated in FIGS. 34 and 36.

Carriage 330 also is provided with fingers 375 which engage a shoulderwall 376 of sharp 324 (as illustrated in FIG. 34), as will be describedin greater detail herein.

In certain embodiments, inserter 300 also includes a spring retentioncomponent 348, as illustrated in FIG. 31. Spring retention component 348defines an upper surface 349, which engages spring 346 (as illustratedin FIG. 34). Spring retention component 348 also includes locking towers351 including projections, which engage apertures 328 of needle carrier334 to prevent accidental deployment of the sharp 324 after use of theinserter 300 is completed.

Inserter 300 is illustrated in cross-section in FIG. 33 prior to use.Cap 304 is attached to the distal portion of inserter 300, viasecurement means, such as inter-engagement of threads 310 and 311. Cap304 includes a desiccant tablet 390; a seal, such as a foil seal 392;and a Tyvek® layer 394, which allows breathability between the desiccanttablet 390 and the interior of the inserter 300.

As illustrated in FIG. 34, the inserter 300 includes an initialconfiguration in which the handle 302 is disposed in a proximal positionwith respect to the sheath 342. In such configuration, the sharp 324 isdisposed in a configuration spaced apart from the aperture 320 of theadhesive layer 318. The distal portion of inserter 300 is illustrated inFIG. 35.

With continued reference to FIG. 34, the longitudinal axis L of theinserter 300 is illustrated. Extending distally from the upper surfaceof handle 302 is an inner wall portion 326 and intermediate wall portion374. Support member 334 extends from wall portion 326 and supportsneedle hub 336, from which sharp 324 extends longitudinally within theinserter 300. In some embodiments, the sharp is supported at an obliqueangle, e.g., between 0° and 90° with respect to the skin surface.

Sheath 342 is positioned within handle 302, having an annularconfiguration in which a refraction spring 346 is positioned. The distalportion of spring 346 contacts a surface 349 of spring retentioncomponent 348. The proximal portion of spring 346 contacts the innersurface 350 of handle 302. In the initial configuration, the spring 346is in an extended or semi-extended configuration.

FIG. 36 illustrates inserter 300 in cross-section, during insertion.Depression of handle 302 with respect to sheath 342 against the bias ofspring 346 causes distal longitudinal movement of the carriage 330 andsharp 324, from a proximal position towards a distal position. Duringsuch downward, distal movement, spring 346 is compressed between surface349 of spring retention component 348 and surface 350 of handle 302. Asthe sharp 324 is urged distally by housing 302, it carries the sensorinsertion portion 30 of sensor 14 into the subject's skin S.

As carriage 330 reaches a distal position, the distal surface of the onbody housing 122 engages the upper surface of adhesive pad 318, therebybecoming adhered to the skin surface S of the subject. Also, flange 370engages fingers 375 disposed on the carriage 330. Fingers 375 arepivoted outwards by flanges 370 in direction T. Such pivoting of fingers375 causes fingers 375 to become disengaged from slots 376 inintermediate housing walls 374. Carriage 330 is thereby disengaged fromhandle 302 and needle carrier 334.

As illustrated in FIG. 37, handle 302, along with needle hub 336 andsharp 324 are permitted to move proximally, while the sheath 342 and onbody housing 122 remain adjacent to the skin of the subject. If the useror some apparatus provides no downward force, or minimal downward forceto the handle 302 to overcome the bias of spring 346, spring 346 ispermitted to expand, thereby withdrawing the sharp 324 from the skin Sof the subject.

Upon reaching the proximal position, flanges 328 on needle carrier 334engage locking towers 351 of needle floor component 348. Theinter-engagement of flanges 328 and locking towers 351 preventsinadvertent deployment of sharp 324 after installation of the medicaldevice.

A further embodiment of an inserter is illustrated in FIGS. 40-50, anddesignated inserter 400. In some embodiments, inserter 400 has a maximumdiameter of about 30 mm to about 60 mm, e.g., about 40 mm, about 43 mm,about 43.5 mm, about 50.5 mm, about 54.5 mm, etc. In some embodiments,inserter 400 has a maximum height of about 40 mm to about 80 mm, e.g.,about 44 mm, about 46 mm, about 50 mm, about 53 mm, about 67 mm, about71 mm, etc. In some embodiments, inserter 400 has a volume of about 35cm³ to about 110 cm³, e.g., about 40 cm³, about 41 cm³, about 50 cm³,about 60 cm³, about 61 cm³, about 62 cm³, about 69 cm³, about 70 cm³,about 79 cm³, about 90 cm³, about 106 cm³, etc. The maximum height ismeasured from the top of the housing 402 to the distal surface 412. Thevolume is measured as the combined volume of the housing 402 and thesheath 442 in an expanded position. the combined volume of the housing402 and the sheath 442 in an expanded position.

Inserter 400 generally includes, e.g., a handle 402, sheath 442, and aremovable distal cap 404 for maintaining a sterile environment for themedical device and sharp housed therein. As illustrated in FIG. 41,distal cap 404 is shown removed from handle 402. Distal cap 404 isdetachably secured to handle 402, e.g., by use of threads 410. Sheath442 includes a distal surface 412 for placement on the skin of asubject. Inserter 400 may be utilized to advance a medical device intothe skin of the subject. In some embodiments, handle 402 is advancedrelative to sheath 442 in order to advance the medical device distallyand into the skin of the patient.

The components of inserter 400 are illustrated in FIGS. 42-46. Asillustrated in FIG. 42, handle 402 includes threads 410 for attachmentof cap 404 via threads 411 (as illustrated in FIG. 44). Cap 404 mayinclude a receptacle 425 for positioning of the sharp 424. Sheath 442,as illustrated in FIG. 43, includes longitudinal notches 482.Projections 486 on carriage 430, as illustrated in FIG. 45, areconfigured to engage sheath 442 to secure carriage 430 within inserter400, thereby preventing release of the carriage from the inserter.Sheath 442 also includes notches 484 which receive projection 475 ofcarriage 430. The bottom of the notches acts as the retention portionthat prevents the carriage 430 from falling out of the inserter 400.Projections 475 engage with the latch features 470 of the sheath 442 asillustrated in FIGS. 49 and 50. Carriage 430 also is provided withfingers 474 which engage a shoulder wall 476 of needle carrier 436, asillustrated in FIGS. 48-49, and as will be described in greater detailherein.

Sheath 442 also includes a spring retention portion 448, provided at thedistal end of circumferential notch 496, as illustrated in FIG. 48.Needle carrier 434, as illustrated in FIG. 46, includes wings 450, whichprovide an upper engagement surface for spring 446. Wings 450 alsoinclude a shoulder 476 for engagement with fingers 474 of carriage 430.

Inserter 400 is illustrated in cross-section in FIG. 47 in a state priorto use and prior to removal of cap 404, which is shown attached to thedistal portion of handle 402, via inter-engagement of threads 410 and411. Cap 404 includes a desiccant tablet 490, a seal such as a foil seal492, and a Tyvek® layer 494, which allows breathability between thedesiccant tablet 490 and the interior of the inserter 400.

As illustrated in FIG. 48, the inserter 400 is shown in an initialconfiguration in which handle 402 is disposed in a proximal positionwith respect to the sheath 442. In such configuration, the sharp 424 isdisposed in a configuration spaced apart from the aperture 420 of theadhesive layer 418. The longitudinal axis L of the inserter 400 isillustrated. Extending distally from the upper surface of handle 402 isinner wall 475. The distal end portions of wall 475 provide a downwardforce on the carriage 430 upon depression of the handle 402 by a user.Alternatively, instead of handle having a distally extending inner wall,the carriage can include one or more upwardly extending walls orprojections (not shown). The one or more upwardly extending inner wallsor projections can have a length sufficient to either contact the uppersurface of 402 or, alternatively, contact corresponding downwardlyextending inner walls of the handle 402. In this manner, depression ofhandle 402 by a user provides a downward force on the one or moreupwardly extending walls or projections of the carriage to advance thecarriage (and on-body unit) distally to an installation and insertionposition. (See FIGS. 49-50.) In one embodiment a downwardly extendingwall of the handle 402 and a corresponding upwardly extending wall ofthe carriage are aligned such that depression of the handle 402 by auser allows the upwardly extending wall and the downwardly extendingwall to make direct contact, thereby permitting the carriage 430 andon-body unit to advance distally. In such embodiment, the downwardlyextending inner wall of the handle has a distal end that is disposedproximally of the proximal most end of sheath 442.

Needle carrier 434 can be axially moveable within handle 402. Needlecarrier 434 supports needle hub 436, from which sharp 424 extendslongitudinally within inserter 400. In some embodiments, sharp 424 issupported at an oblique angle, e.g., between and including about 0° and90° with respect to the skin surface. Initially, needle carrier 434 iscoupled to carriage 430 via inter-engagement of fingers 474 of carriage430 with shoulder 476 of needle carrier 434. Spring 446 is disposedbetween spring retention portion 448 of sheath 442 and wings 450 (FIG.46) of needle carrier 434. Initially, spring 446 is in an expanded orsemi-expanded state while handle 402 is disposed proximally from sheath442. In another exemplary embodiment, needle carrier 434 can be securedto handle 402, for example, secured to downwardly extending inner wall475. In this manner, needle carrier and carriage 430 are longitudinallymoveable along the line defined by L shown in FIG. 48 with respect tosheath 442. In this regard, needle carrier 434 includes one or moreapertures to receive one or more downwardly extending inner walls 475 ofhandle 402. In some embodiments, neither the needle carrier 434 nor thecarriage 430 are in slidable contact with sheath 442, e.g., spaced apartfrom sheath 442, during longitudinal movement of the needle carrier 434and/or carriage 430.

FIG. 49 illustrates inserter 400 in cross-section, during insertion.Depression of handle 402 with respect to sheath 442, against the bias ofspring 446, causes distal longitudinal movement of the carriage 430 andneedle carrier 434, from a proximal position towards a distal position.During such downward proximal movement, spring 446 is compressed betweenspring retention portion 448 and wings 450 (FIG. 46) of needle carrier434. As the sharp 424 is urged distally, it carries the sensor insertionportion 30 of sensor 14 (FIG. 17) into the subcutaneous portion of thesubject's skin S.

As carriage 430 reaches a distal position (close to the skin of thesubject), the distal surface of the on body housing 122 engages theupper surface of adhesive pad 418, thereby becoming adhered to the skinsurface S of the subject. Flange 470 engages fingers 474 disposed on thecarriage 430. Fingers 474 are pivoted outwards by flanges 470 indirection T. Such pivoting of fingers 474 causes fingers 474 to becomedisengaged from shoulder 476 of needle carrier 434. Needle carrier 434is thereby disengaged from carriage 430. Such pivoting of fingers 474also engages opening in 474 with flange 470, thus locking carriage 430in the distal position.

As illustrated in FIG. 50, disengagement of the needle carrier 434 fromthe carriage 430 permits the spring 446 to expand, thereby advancing theneedle carrier 434 to a proximal position (away from the skin of thesubject) and withdrawing the sharp 424 from under the skin surface S ofthe subject while leaving the sensor 14 in the skin. Once the sharp 424has been withdrawn from the subject, it is no longer accessible from thedistal portion of the inserter 400 and unable to make contact byaccident with the subject's skin because it is positioned at a proximalposition within the carrier handle 402.

An inserter 2400 in accordance with another exemplary embodiment isillustrated in FIG. 51. In some embodiments, inserter 2400 has a maximumdiameter, of about 30 mm to about 60 mm, e.g., about 40 mm, about 43 mm,about 43.5 mm, about 50.5 mm, about 54.5 mm, etc. In some embodiments,inserter 2400 has a maximum height of about 40 mm to about 80 mm, e.g.,about 44 mm, about 46 mm, about 50 mm, about 53 mm, about 67 mm, about71 mm, etc. In some embodiments, inserter 2400 has a volume of about 35cm³ to about 110 cm³, e.g., about 40 cm³, about 41 cm³, about 50 cm³,about 60 cm³, about 61 cm³, about 62 cm³, about 69 cm³, about 70 cm³,about 79 cm³, about 90 cm³, about 106 cm³, etc. The height is measuredfrom the distal surface of the housing 2402 (adjacent to adhesive 218)to the top surface. The volume is measure by the volume of the housing2402.

With reference to FIG. 51, inserter 2400 includes a housing 2402 and aremovable distal cap 2412 for protecting the medical device and sharphoused therein. Housing 2402 and distal cap 2412 may be fabricated fromany suitable materials such as metal, plastic, etc. In some embodiments,cap 2412 may be fabricated from a polymer or plastic material.

An exploded view of the components of inserter 2400 is illustrated inFIG. 52. As shown, inserter 2400 generally comprises plunger 2405,spring 2406, housing 2402, sharp 2404 (not shown in FIG. 52), on bodyhousing 122, sharp holder 2408, adhesive patch 218, and cap 2412 whenfully assembled.

A more detailed view of sharp holder 2408 is shown in FIG. 53. Needleholder 2408 retains sharp 2404 in a fixed position with respect toitself within inserter 2400, thereby allowing it to safely penetrate asubject's skin during later use.

To assemble inserter 2400, sharp 2404 and hub 2408 are inserted throughan opening in on body housing 122 as shown in FIG. 54. Needle holder2408 prevents sharp 2404 from being fully inserted through on bodyhousing 122. In some embodiments, on body housing 122 includes ananalyte sensor 14 and on body electronics 1100.

Next, plunger 2405, spring 2406, and housing 2402 are assembled as shownin FIGS. 55-57. Plunger 2405 contains a spring retention member which isinserted through the center of spring 2406. Lip 2414 of plunger 2405engages inner wall 2416 of housing 2402 when assembled (FIG. 51). Thiscauses spring 2406 to be contained between lip 2418 of housing member2402 and the bottom surface 2424 of plunger 2405. The resultingsub-assembly of inserter 2400 shown in allows plunger 2405 to movebetween a proximal position, with spring 2406 in a preloaded condition,and a distal position, wherein bottom surface 2424 engages wall 2426 ofhousing 2402.

The on body housing assembly shown in FIG. 54 is then inserted into theinserter sub-assembly shown in FIGS. 55-57. As shown in FIG. 57, on bodyhousing 122 is inserted into housing 2402 with the tip of sharp 2404pointing away from plunger 2405. The resulting assembly is depicted inFIG. 58. As shown in FIG. 51, grooves on sharp holder 2408 engage tabs2422 on plunger 2405. The on body housing 122 is axially retained in thehousing 2402 by the housing arms detent features 2440.

Finally, adhesive patch 218 is placed over the opening of housing 2402and cap 2412 is friction fit over housing 2402 as shown in FIG. 59. Thefully assembled inserter 2400 is depicted in FIG. 60. In someembodiments, adhesive pad 218 has an adhesive material on both faces. Acentral aperture 220 may be provided in adhesive pad 218 to allow sharp2404 to be deployed into the skin of a subject. During insertion, sharp2404 passes through aperture 220 and into the skin of the subjectcarrying at least the sensor with it.

FIG. 61 illustrates inserter 2400 in cross-section, in an initialconfiguration prior to use, after removal of the distal cap 2412. Asshown, sharp 2404 extends longitudinally within the inserter 2400. Insome embodiments, sharp 2404 is supported at an oblique angle, e.g.,between and including about 0° and 90° with respect to the skin surface.

In some embodiments, sharp 2404 is provided with a substantiallycylindrical configuration defining an interior bore, e.g., a rigidcylindrical member or a hypodermic-style needle. Sharp 2404 may also beprovided with an elongated longitudinal opening or gap in the wall ofthe sharp 2404. In some embodiments, sharp 2404 is fabricated from asheet of metal, and folded into a substantially “V” or “U” or “C”configuration in cross-section to define the longitudinal recess.

Depression of plunger 2405 causes distal longitudinal movement of onbody housing 122 and sharp 2404, from a proximal position to a distalposition. During such downward, distal movement, spring 246 is furthercompressed between lip 2418 and bottom surface 2424. Detent 2440provides a minimum force threshold to overcome before on body housing122 can continue on its downward distal movement. Beyond a minimum forcethreshold, detent 2440 is pushed outward by on body housing 122, and onbody housing 122 then translates onto ramp 2442. The friction between onbody housing 122 and ramp 2442 of the housing hold the on body housing122 up against plunger 2405.

As illustrated in FIG. 62, depression of plunger 2405 advances theinserter 2400 from an initial configuration to a deployed configuration.Contact of plunger 2405 and hub 2408 during depression of plunger 2405imposes a downward force and consequential distal movement of sharp2404. As the sharp 2404 is urged distally, it carries the sensorinsertion portion 30 into the subcutaneous portion of the subject's skinS. Contact of plunger 2405 and sensor housing 122 during depression ofplunger 2405 imposes a downward force and consequential distal movementof sensor housing 122. Lip features 2414 of plunger 2405 maintainparallelism of sensor housing 122 to subject skin S during distalmovement.

When plunger 2405 reaches a distal position, as shown in FIG. 63, bottomsurface 2424 engages wall 2426 and prevents further downward movement.The distal (lower) surface of on body housing 122 engages the uppersurface of adhesive pad 218, thereby becoming adhered to the skinsurface S of the subject.

As the subject or some apparatus removes force from plunger 2405, spring2406 urges plunger 2405 toward its proximal position (away from the skinsurface) as shown in FIG. 64, leaving on body housing 122 adhered to theskin surface S of the subject. Tabs 2427 provide additional downwardforce to the on body housing 122 to assist holding it to adhesive patch218 while the sharp 2404 is withdrawn through on body housing 122.Eventually, the upward force exerted by spring 2406 returns inserter2400 to its initial configuration as illustrated in FIG. 65.

In some embodiments, inserter 2400 may be distributed in a sterilizedpackage 2480 as depicted in FIG. 66. To use inserter 2400 in thisconfiguration, a user would first clean the insertion site on the skinwith alcohol. The user would then remove inserter 2400 from sterilizedpackage 2480 as shown in FIG. 66. Next a user would place the inserteron the insertion site and push down on plunger 2405 until on bodyhousing 122 is adhered to the subject's skin as shown in FIGS. 67-68.The user would then release the plunger 2405. Finally, the user wouldremove inserter 2400 from the insertion site and dispose of theinserter.

A further embodiment of an inserter is illustrated in FIGS. 73-87, anddesignated inserter 2500. In some embodiments, inserter 2500 has amaximum diameter of about 30 mm to about 60 mm, e.g., about 40 mm, about43 mm, about 43.5 mm, about 50.25 mm, about 52 mm, etc. In someembodiments, inserter 2500 has a maximum height of about 40 mm to about80 mm, e.g., about 44 mm, about 46 mm, about 50.25 mm, about 53 mm,about 67 mm, about 71 mm, etc. In some embodiments, inserter 2500 has avolume of about 35 cm³ to about 110 cm³, e.g., about 40 cm³, about 41cm³, about 50 cm³, about 60 cm³, about 61 cm³, about 62 cm³, about 69cm³, about 70 cm³, about 79 cm³, about 90 cm³, about 106 cm³, etc. Theheight of the inserter is measured from the top of housing 2502 to thedistal surface of the sheath 2512 that is intended to contact the skinof the subject. The volume of the inserter may be measured as the volumeof the housing and the portion of the sheath 2512 that may extend fromthe housing 2502.

Inserter 2500 generally includes, e.g., a handle 2502, sheath 2512, anda removable distal cap 2504 for maintaining a sterile environment forthe medical device and sharp housed therein (FIG. 73). As illustrated inFIGS. 74-75, handle 2502 is shown removed from distal cap 2504. Distalcap 2504 is detachably secured to handle 2502, e.g., by use of threads2506. It is understood that cap may be secured using snap-fit orpress-fit configuration. Inserter 2500 may be utilized to advance amedical device into the skin of the subject. In some embodiments, handle2502 is advanced relative to sheath 2512 in order to advance the medicaldevice distally and into the skin of the patient.

Handle 2502 further includes needle carrier guides 2508 which allow theneedle carrier 2514 to slidingly move relative to distal cap 2504. In analternate embodiment, a detent prevents sheath 2512 from moving towardsa “firing position” until a minimum force is applied. Location feature2510 allows for the proper positioning of carriage 2516 when engaged.

Further components of inserter 2500 are illustrated in FIGS. 76-80.Sheath 2512, as illustrated in FIGS. 76, may include longitudinalnotches 2518 which snap into detents 2507. Retention members, such asribs 2520, pinch spring arms 2522 located on carriage 2516 to prevent onbody housing 122 from falling out of inserter 2500. Ribs 2520 do notextend to the bottom of sheath 2512, thus allowing carriage 2516 torelease on body housing 122 when it has traveled to the bottom of sheath2512 during insertion. Interfering structure, such as locking beam 2524,prevents inserter 2500 from being used again once needle carrier 2514passes the locking beam (FIG. 87). Specifically, locking feature 2526 ofneedle carrier 2514 engages with locking beam 2524 to prevent furtheruse of inserter 2500.

Needle carrier 2514 is illustrated in greater detail in FIGS. 77-78. Insome embodiments, needle carrier 2514 includes guides, such as railguides 2528, which interface with rail guides 2508, thereby allowingneedle carrier 2514 to slidingly move relative to handle 2502. Notches2527 are provided in sheath 2512 which has a larger dimension than thewings of needle carrier 2514, such that the needle carrier 2514 does notcontact sheath 2512 during longitudinal movement of needle carrier 2514.Needle carrier 2514 also comprises detents/notches 2530 which interfacewith the upper edge of the spring when inserter 2500 is fully assembled(see FIGS. 81-87). In some embodiments, needle carrier 2514 comprises anattachment feature 2532 capable of accommodating a custom needle hub orattachment.

Carriage 2516 is illustrated in greater detail in FIGS. 79-80. As shown,carriage 2516 may comprise latches 2538 which connect it to needlecarrier 2514 by locking with latches 2540. Spring hook 2542 allows forsupport for retaining on body housing 122 when the inserter has not beenfired and allows for release of on body housing 122 when it has beenattached to the skin of the user. (See, FIGS. 122, 125, 135-140.)

Inserter 2500 is illustrated in cross-section in FIG. 81 in a stateprior to use in which handle 2502 is disposed in a proximal positionwith respect to the sheath 2512. In such configuration, the sharp 2550is disposed in a configuration spaced apart from the aperture 420 of theadhesive layer (not shown). The longitudinal axis L of the inserter 2500is illustrated. The upper surface of spring 2544 is retained in inserter2500 by detents/notches 2530 located on needle carrier 2514. The bottomsurface of spring 2544 is retained by spring floor 2545 located onsheath 2512. Initially, spring 2544 is in an expanded or semi-expandedstate while handle 2502 is disposed proximally from sheath 2512.

Extending distally from the upper surface of handle 2502 is inner wall2508. In some embodiments, the distal end portions of wall 2508 providea downward force on carriage 2516 upon depression of handle 2502 by auser. Alternatively, instead of handle 2502 having a distally extendinginner wall 2508, carriage 2516 can include one or more upwardlyextending walls or projections (not shown). The one or more upwardlyextending inner walls or projections of the carriage 2516 can have alength sufficient to either contact the inside of the upper surface ofhandle 2502 or, alternatively, contact corresponding downwardlyextending inner walls of handle 2502. In this manner, depression ofhandle 2502 by a user provides a downward force on the one or moreupwardly extending walls or projections of carriage 2516 to advancecarriage 2516 (and on body housing 122) distally to an installation andinsertion position (FIG. 84). In such embodiment, the downwardlyextending inner wall of the handle has a distal end that is disposedproximally of the proximal most end of sheath 2512.

Sharp 2550 extends longitudinally from needle carrier 2514 withininserter 2500. In some embodiments, sharp 2550 is supported at anoblique angle, e.g., between about 0° and 90° with respect to the skinsurface.

FIG. 82 illustrates inserter 2500 in cross-section after a user appliesan initial downward force to button 2502. Further depression of handle2502 with respect to sheath 2512, against the bias of spring 2544,causes distal longitudinal movement of the carriage 2516 and needlecarrier 2514, from a proximal position towards a distal position asshown in FIG. 83. During such downward proximal movement, spring 2544 iscompressed between detents/notches 2530 and retention tab 2546. As sharp2550 is further urged distally, it carries the sensor insertion portion30 of sensor 14 (FIG. 17) into the subject's skin S.

As carriage 2516 reaches a distal position (near the subject's skin) asshown in FIG. 83, the distal surface of the on body housing 122 engagesthe upper surface of adhesive pad (not shown), thereby becoming adheredto the skin surface S of the subject. Latch 2538 engages the uppersurface of retention tab 2546 as shown in FIGS. 84. As a result, the topportion of latch 2538 is pivoted outward in direction T. Such pivotingof latch 2538 causes needle carrier to become disengaged from carriage2516.

As illustrated in FIG. 85, disengagement of the needle carrier 2514 fromthe carriage 2516 permits spring 2544 to expand, thereby advancing theneedle carrier 2514 to a proximal position and withdrawing the sharp2550 from the skin S of the subject while leaving the on body housing122 attached to the skin. As the sharp is withdrawn (FIG. 86), lockingfeature 2526 advances past locking beam 2524 because of the upward forceexerted on needle carrier 2514 by spring 2544.

Referring now to FIG. 87, once the sharp 2550 has been withdrawn fromthe subject, button 2502 cannot be pressed again because any downwardmovement will be blocked by the interaction of locking beam 2524 andlocking feature 2526.

In some embodiments, inserter 2500 may come in a sterilized packagewhich is capable of a one-time use as shown in FIGS. 88-90. To useinserter 2500 in this manner, a user would first sterilize the insertionsite on the skin with alcohol. The subject would then twist off cap 2504as shown in FIG. 88. Next a subject would place the inserter on thesterilized insertion site and push down on inserter 2500 until on bodyhousing 122 is adhered to the subject's skin as shown in FIGS. 89-90.Finally, the subject would remove inserter 2500 from the insertion siteand dispose of the inserter. In this manner, the inserter 2500 itselfserves as its own sterilized packaging. This procedure applies also tothe other inserters described herein.

A further embodiment of an inserter is illustrated in FIGS. 91-108, anddesignated inserter 2700. In some embodiments, inserter 2700 has amaximum diameter of about 30 mm to about 60 mm, e.g., about 40 mm, about43 mm, about 43.5 mm, about 46 mm, about 50 mm, etc. In someembodiments, inserter 2700 has a maximum height of about 40 mm to about80 mm, e.g., about 44 mm, about 46 mm, about 49.5 mm, about 55 mm, about67 mm, about 71 mm, etc. In some embodiments, inserter 2700 has a volumeof about 35 cm³ to about 110 cm³, e.g., about 40 cm³, about 41 cm³,about 50 cm³, about 60 cm³, about 61 cm³, about 62 cm³, about 69 cm³,about 70 cm³, about 79 cm³, about 90 cm³, about 106 cm³, etc. Themaximum height refers to the height defined from the top of the housing2702 to the portion of the sheath 2708 that contacts the subject's skin.The volume is measured as the volume of the housing 2702 and the portionof the sheath 2708 extending from the housing.

Inserter 2700 generally includes, e.g., a housing 2702 (FIGS. 92-93),sheath 2708 (FIGS. 94-95), and a removable distal cap 2704 formaintaining a sterile environment for the medical device and sharphoused therein (FIG. 91). As illustrated in FIGS. 92-93, housing 2702 isshown removed from distal cap 2704. Distal cap 2704 is detachablysecured to housing 2702, e.g., by use of threads 2706. It is understoodthat cap may be secured using snap-fit or press-fit configuration.Inserter 2700 may be utilized to advance a medical device into the skinof the subject. Sheath 2708 generally defines a cavity or open space,within which sharp carrier 2716 and medical device carrier 2730 aremoveable. In some embodiments, housing 2702 is advanced relative tosheath 2708 in order to advance the medical device distally and into theskin of the patient.

Housing 2702 includes sheath guide rail 2710 which interfaces with railguides 2712 located on sheath 2708 (FIG. 94), thereby allowing housing2702 to slidingly move longitudinally relative to sheath 2708. Housing2702 may further includes sharp carrier guide rail 2714 which interfaceswith rail guides 2718 located on sharp carrier 2716 (FIG. 97). Sheath2708, sharp carrier 2716, and housing 2702 may alternatively moverelative to one another without the use of guide rails.

Ledge 2720 and/or ledge 2722 are provided on an interior portion ofhousing 2702. Ledge 2720 engages sheath 2708 to hold sheath 2708 in apre-use position prior to insertion of the medical device. Ledge 2722engages sheath 2708 to secure sheath 2708 in a post-use position afterinsertion of the medical device. Housing 2702 further includes detent2724 which prevents housing 2702 from moving relative to sheath 2708until a minimum force has been applied, e.g., distally by user tohousing 2702. The sheath 2708 is secured to the housing 2702 via snap2726. Snap 2726 snaps into the housing detent 2724. (In someembodiments, it is pinched between ledge 2720 and detent 2724, thuscontrolling its longitudinal position relative to the housing 2702). Theneedle carrier 2716 is located and secured to the medical device carrier2730 (located via interaction of locating features 2748 and 2750 andsecured via interaction of carrier arms 2732 and angled top surface of2716). The ledge 2720 is a controlled surface onto which the top ofsheath surface 2728 will engage at the end of the insertion stroke toprevent further relative movement in some embodiments.

Further components of inserter 2700 are illustrated in FIGS. 94-99.Sheath 2708 is a generally cylindrical component. As illustrated inFIGS. 94-95, sheath 2708 may include attachment snaps 2726 which arebiased into detent 2724 of housing 2702 to create a minimum force thatmust be overcome in order to advance sharp 224 into the subject's skinand install the on body housing 122. The interaction of the snap 2726with the detent 2724 and ledge 2720 holds the assembly in a slop/rattlefree position. In some embodiments, the force to be overcome can beabout 0.5 lbf to about 5 lbf., e.g., about 1 lbf, about 2 lbf, about 3lbf, about 4 lbf, etc. Support wall 2728 prevents carrier arms 2732 oncarrier 2730 from bending outwardly, clear of sharp carrier 2716. Ribs2734 pinch carrier arms 2732 on carrier 2730, thus preventing on bodyhousing 122 from falling out of inserter 2700 when sheath 2708 is in theextended position. Ribs 2734 are not present at the bottom of sheath2708, thus allowing room for spring arms 2736 on carrier 2730 to releaseon body housing 122 when carrier 2730 has traveled to the bottom ofsheath 2708. Slot 2738, located on sheath 2708, interfaces with locatingfeature 2740 on carrier 2730, thus orienting carrier 2730 to sheath 2708during assembly. Once force is overcome to allow carrier 2730 to movedistally towards the subject's skin, no further force is required toretract the sharp 324 from the subject's skin.

Referring next to FIGS. 96-97, depicted is sharp carrier 2716 in aperspective and cross-sectional view, respectively. Sharp carrier 2716contains notches 2724 which allow clearance for the passage of carrierarms 2732 located on medical device carrier 2730. Guidance walls 2744securely hold spring 2746 in place (FIG. 100). Locating features 2748,e.g., bosses or tabs, align with locating features 2750, e.g., recessesor apertures, on carrier 2730. Snap features 2752 secure sharp 224securely within inserter 2700. It is contemplated that sharp 224 may besecured to sharp carrier 2716 by other techniques, e.g., friction fit,adhesive, welding, etc.

Medical device carrier 2730 is depicted in more detail in FIGS. 98-99.As shown, carrier 2730 contains spring locating ring 2754 which receivesone end of spring 2746. In some embodiments, spring 2746 surroundsspring locating ring 2754. In some embodiments, the inner area remainsclear to leave room for the deflection of sharp carrier feature snaps2752 that move outwardly when the sharp is inserted. Carrier 2730further comprises locating features 2756 which interface with locatingfeatures on housing 2702. (See FIGS. 135-136).

Inserter 2700 is illustrated in cross-section in FIG. 100 in a stateprior to use in which housing 2702 is disposed in a proximal positionwith respect to the sheath 2708. In such orientation, sharp 224 isdisposed in a configuration spaced apart from the aperture 420 of theadhesive layer 118. The upper surface of spring 2746 is retained ininserter 2700 by sharp carrier 2716. The bottom surface of spring 2746is retained by spring location ring 2754. Initially, spring 2746 is in acompressed or semi-compressed state while housing 2702 is disposedproximally from sheath 2708.

Sharp 224 extends longitudinally from sharp carrier 2716 within inserter2700. In some embodiments, sharp 224 is supported at an oblique angle,e.g., between and including about 0° and 90° with respect to the skinsurface.

FIG. 101 illustrates inserter 2700 in cross-section after a user appliesan initial downward force to housing 2702. In some embodiments, apredetermined minimum force must be used so that attachment snaps 2726advance past detent 2724.

After detent 2724 has been overcome, e.g., snap 2726 is radiallydisplaced, further depression of housing 2702 with respect to sheath2708 causes distal longitudinal movement of the carrier 2730 and sharpcarrier 2716, from a proximal position towards a distal position asshown in FIG. 103. As sharp 224 is further urged distally, it carriesthe sensor insertion portion 30 of sensor 14 (FIG. 17) into thesubcutaneous portion of the subject's skin S.

As carrier 2716 reaches a distal position (FIG. 103), the distal surfaceof the on body housing 122 engages the upper surface of adhesive pad2718, thereby becoming adhered to the skin surface S of the subject.Concurrently, carrier arms 2732 are advanced distally and clear thesupport wall 2728. This allows carrier arms 2732 to deflect radiallyoutwardly. (See, FIG. 104). When carrier arms 2732 deflect radiallyoutwardly, shoulder portions of carrier arms 2732 are no longer in aninterference relationship with the sharp carrier 2716. Thus spring 2746is permitted to expand as shown in FIG. 105, thereby advancing the sharpcarrier 2716 to a proximal position and withdrawing the sharp 224 fromthe skin S of the subject while leaving the on body housing 122 attachedto the skin. Handle 2702 is maintained in the distal position. Sheathsnap 2726 of the sheath 2708 have now moved up to lock over feature 2722of the housing 2702. Now the housing 2702 and the sheath 2708 can nolonger move longitudinally with respect to each other, and provides anindication to a user that the inserter has been used. In FIG. 106, themedical device carrier 2730 acts as a needle guard to prevent a user fortouching the needle.

In some embodiments, the changing interaction of sheath snap 2726 withthe housing detent/ledges 2720, 2724, and 2722 determine whether thesheath 2708 is locked. When snap 2726 is in the pre-fire position, ledge2720 prevents sheath 2708 from being pulled out of the housing 2702. Inthis position, detent 2724 may also impede the movement of pushing thesheath 2708 into the housing 2702. When the detent is overcome by atleast a minimum force, the sheath 2704 moves longitudinally with respectto the housing 2702 until the snap 2726 snaps over housing ledge 2722.At this point, ledge 2722 prevents the sheath 2708 from being pulled outof the housing again, but from a new position (this position may bereferred to as the used/post-fire position). Sharp carrier snap 2752function is to hold onto the sharp 224. In some embodiments, the sharpcarrier 2716 is held in the post-fire position relative to the housing2702 by, e.g., an interference between the rails of the housing 2714 andthe guide rails of the sharp carrier 2718 (this interference is onlypresent once the sharp carrier is fully retracted) and/or by medicaldevice carrier projections interfering with the bottom/floor of thesharp carrier (See, e.g., FIG. 106). In another embodiment of inserter2700, adhesive pad 118 may be attached directly to on body housing 122.This necessitates a different shape of inserter 2700 as depicted in FIG.107. Additionally, carrier 2730 is slightly wider to accommodateadhesive pad 118 attached to on body housing 122 (FIG. 108).

A further embodiment of an inserter is illustrated in FIGS. 109-134. Insome embodiments, inserter 3700 has a maximum diameter of about 30 mm toabout 60 mm, e.g., about 40 mm, about 43 mm, about 43.5 mm, about 46 mm,about 50 mm, etc. In some embodiments, inserter 3700 has a maximumheight of about 40 mm to about 80 mm, e.g., about 44 mm, about 46 mm,about 49.5 mm, about 55 mm, about 67 mm, about 71 mm, etc. In someembodiments, inserter 3700 has a volume of about 35 cm³ to about 110cm³, e.g., about 40 cm³, about 41 cm³, about 50 cm³, about 60 cm³, about61 cm³, about 62 cm³, about 69 cm³, about 70 cm³, about 79 cm³, about 90cm³, about 106 cm³, etc. The maximum height refers to the height definedfrom the top of the housing 3702 to the portion of the sheath 3708 thatcontacts the subject's skin. The volume is measured as the volume of thehousing 3702 and the portion of the sheath 3708 extending from thehousing.

FIGS. 109-112 depict the various stages of insertion from an initialstage in which the cap is attached (FIG. 109), to removal of the cap(FIG. 110), deployment of the sharp and on body housing unit (FIG. 111)and removal of the inserter from the subject's skin (FIG. 112).

Inserter 3700 generally includes, e.g., a housing 3702 (FIGS. 109,113-114), sheath 3708 (FIGS. 115-116), and a removable distal cap 3704(FIGS. 117-119) for maintaining a sterile environment for the medicaldevice and sharp housed therein. As illustrated in FIGS. 109 and117-119, housing 3702 is shown removed from distal cap 3704. Distal cap3704 is detachably secured to housing 3702, e.g., by use of threads3706. It is understood that in some embodiments, the cap may be securedusing snap-fit or press-fit configuration.

Inserter 3700 may be utilized to advance a medical device into the skinof the subject. Sheath 3708 generally encloses or defines a cavity,within which sharp carrier 3716 (FIGS. 120-121) and medical devicecarrier 3730 (FIG. 122) are moveable. In some embodiments, housing 3702is advanced relative to sheath 3708 in order to advance the medicaldevice distally and into the skin of the patient.

Housing 3702 includes sheath guide rail 3710 which interfaces with railguides 3712 located on sheath 3708, thereby allowing housing 3702 toslidingly move relative to sheath 3708. Sheath 3708, sharp carrier 3716,and housing 3702 may alternatively move relative to one another withoutthe use of guide rails. The housing can include a distally extendingsidewall having a non-linear or arcuate shape. In the embodimentillustrated in FIGS. 109-134 the housing is configured with anundulating sidewall which transitions from a concave portion (upperportion of housing 3702) to a convex portion (lower portion of housing3702). (FIG. 114). This contour enhances the users tactile recognitionand provides a more ergonomic gripping surface which reduces accidentalslippage by the user's hand. Further, the housing is configured with acavity sized to receive the sheath 3708, as described in further detailbelow.

Housing ledge 3720 and/or ledge 3722 are provided on an interior portionof housing 3702. Ledge 3720 engages sheath 3708 to hold sheath 3708 in apre-use position prior to insertion of the medical device. Ledge 3722engages sheath 3708 to secure sheath 3708 in a post-use position afterinsertion of the medical device. Housing 3702 further includes detent3724 which prevents housing 3702 from moving relative to sheath 3708until a minimum force has been applied, e.g., distally by user tohousing 3702. The sheath 3708 is secured to the housing 3702 viaretention features 3726, which can be configured, e.g., as a snap.Retention feature 3726 snaps into the housing detent 3724 (In someembodiments, it is pinched between ledge 3720 and detent 3724, thuscontrolling its height relative to the housing 3702). In someembodiments, the surfaces of the housing ledges 3720, 3722, 3724 andretention features 3726 are configured to engage in a single point ofcontact or a plurality of discrete points of contact, e.g., line. Suchdiscrete points of contact are advantageous over conformalsurface-to-surface contact in that a more thorough sterilization processcan be performed. A variety of sterilization mediums can be employed,e.g., Ethylene Oxide (EtO), wherein the gaseous medium is delivered overthe various inserter components. Accordingly, the discrete points ofcontact allow for a greater surface area of each inserter component tobe exposed to the gaseous medium, thereby providing for a more thoroughand rapid sterilization process. The housing includes distally extendingprotrusions 3727 which are received in apertures 3756 of the medicaldevice carrier 3730 to couple the housing and medical device carrier, bysuch techniques as, e.g., heat staking, ultrasonic bonding, adhesivebonding, snap fit, etc. Coupling the housing and the medical device isperformed, in some embodiments, by e.g., heat staking, ultrasonicbonding, adhesive bonding, snap fit, etc. Consequently, there is norelative movement between the housing 3702 and the medical devicecarrier 3730.

Sheath 3708 is generally formed as a unitary tubular member havingproximal 3708 a and distal 3708 c cylindrical portions. In someembodiments, the portions 3708 a and 3708 c have an elliptical, square,hexagonal, or other cross-section. As illustrated in FIGS. 115-116, thedistal cylindrical portion 3708 c (i.e., the lower portion) can beformed with a greater diameter than the proximal portion 3708 a, withthe proximal and distal portions integrally connected via a shelf 3708b. Accordingly, the sheath 3708 can be formed as a single-piece andgenerally cylindrical member with the proximal portion having sufficientrigidity to prevent displacement of the carrier arms 3732, as describedin further detail below. Sheath 3708 can include retention members 3726,e.g., detent snaps, which are biased into detent 3724 of housing 3702 tocreate a minimum force that must be overcome in order to advance sharp324 into the subject's skin and install the on body housing 322. Theretention members 3726 can extend proximally from the shelf 3708 b ofthe sheath and be formed as a separate member such that the retentionmembers are spaced or offset from the cylindrical wall of the sheath.The actuation force of the inserter is determined by the stiffness ofretention members 3726 (which is a function of length, thickness, andcross section) as well as the steepness of the angle of detent 3724 ofthe housing. In some embodiments, the force to be overcome can be about0.5 lbf to about 5 lbf., e.g., about 1lbf, about 2 lbf, about 3 lbf,about 4 lbf, etc.

As described above, the proximal portion 3708 a of the sheath is sizedsuch that an interior support wall surface 3728 prevents carrier arms3732 on medical device carrier 3730 from displacement or bendingoutwardly, clear of sharp carrier 3716. Maintaining the carrier arms3732 in a fixed or constrained position within the sheath allows a userto accurately know the relative positioning of the needle within theinserter. Conversely, the distal portion 3708 c of the sheath is sizedsuch that the diameter of the interior wall surface is greater than thecarrier arms 3732, thus allowing room for spring arms 3732 on carrier3730 to expand or displace radially outward thereby releasing the sharpcarrier 3716 to retract to the proximal position. Guide rails 3712 areincluded on the exterior surface of the proximal portion of the sheath3708 a. The guide rails 3712 remain engaged with the housing guide rail3710 of the housing throughout the insertion operation, i.e., fromadvancement of the housing from the proximal position to the distalposition. Thus even prior to insertion, rotational position of thehousing and sheath is controlled and “rocking” is minimized. In general,rocking is minimized by increasing the length of engagement with respectto the diameter of engagement. In the embodiment disclosed herein, thelength of engagement between the sheath and housing, i.e. along thelongitudinal axis, is relatively large while the diameter at which theengagement occurs is relatively small, i.e. at proximal portion ofsheath 3708 a. Additionally, sheath 3708 includes a slot 3738 extendingdistally from the shelf 3708 b and configured to receive the guide rail3710 of the housing upon delivery of the medical device and insertion ofthe sharp into the subject.

Referring next to FIGS. 120-121, depicted is sharp carrier 3716 in aperspective and cross-sectional view, respectively. Sharp carrier 3716contains notches 3724 which allow clearance for the passage of carrierarms 3732 located on medical device carrier 3730. Guidance walls 3744securely hold spring 3746 in place (FIGS. 127-128). The top or proximaledge of the sharp carrier includes a chamfered or sloped edge 3725.Locating features 3748, e.g., standoffs or distally extendingprotrusions, aligned with locating features 3750, e.g., recesses orapertures, on carrier 3730. Accordingly, the sharp carrier 3716 islocated and secured to the medical device carrier 3730 (located viainteraction of locating features 3748 and 3750 and secured viainteraction of carrier arms 3732 and angled edge surface of 3725. Theselocating features can extend through the medical device carrier 3730 anddirectly engage the on body housing 322. Accordingly, when a useractuates the inserter, the sharp carrier drives the on body housing 322and sharp 324 towards the subject via the protrusions 3748. The directcoupling of the sharp carrier enhances the control of the positioning ofon body housing 322, and prevents skewing of the on body housing 322 orsharp 324. Additionally, snap features 3752 secure sharp 324 securelywithin inserter 3700. It is contemplated that sharp 324 may be securedto sharp carrier 3716 by other techniques, e.g., friction fit, adhesive,welding, etc.

Medical device carrier 3730 is depicted in more detail in FIG. 122. Asshown, carrier 3730 contains spring locating ring 3754 that receives oneend of spring 3746. In some embodiments, spring 3746 surrounds springlocating ring 3754. In some embodiments, the inner area remains clear toleave room for the deflection of sharp carrier feature snaps 3752 thatdeflect out when the sharp is inserted. As described above, carrier 3730further comprises locating features 3756 which interface with locatingfeatures on housing 3702. Furthermore, detents can be formed at the endof carrier arms 3732 of the medical device carrier to abut or otherwisethe sloped edge 3725 of the sharp carrier. As described above, thedetents on carrier arms 3732 are configured to engage the edge 3725 ofthe sharp carrier in a discrete point of contact fashion in order torealize the aforementioned sterilization advantages. Additionally, thesesurfaces can be configured with rounded surfaces that ensure that thereis no surface to “snag” during the release of the sharp carrier. Themedical device carrier 3700 further includes one or more housinggripping arms 3762 (e.g., three are depicted in FIG. 122) which hold theon body housing 322 in place. In some embodiments, gripping arms 3762are provided with engagement boss 3764 which are configured to engagewith corresponding recesses 3766 provided on the side walls of the onbody housing 322. Such engagement of the recesses 3766 with the grippingarms 3762 maintains the proper height location of the on body housing322. Ribs 3768 or other projections on the interior surface of thedistal portion 3708c of the sheath 3708 hold these gripping arms 3762securely in place against the on body housing 322 while the sheath isfully extended. When the medical device carrier 3730 advances along thesheath 3708 to reach the proximal position during use, the gripping arms3762 are no longer supported by the sheath 3708 and the force of theadhesive skin patch 318 overcomes the retention force of the grippingarms 3762.

Inserter 3700 is illustrated in cross-section in FIGS. 123-125 in astate prior to use in which housing 3702 is disposed in a proximalposition with respect to the sheath 3708 and the cap 3704 secured to thehousing. FIG. 126 illustrates a cross-sectional view of the inserter ina state prior to use after the cap 3704 has been removed. The uppersurface of spring 3746 is retained in inserter 3700 by sharp carrier3716. The bottom surface of spring 3746 is retained by spring locationring 3754 of the medical device carrier 3730. Initially, spring 3746 isin a compressed or semi-compressed state while housing 3702 is disposedproximally from sheath 3708.

Sharp 324 extends longitudinally from sharp carrier 3716 within inserter3700. In some embodiments, sharp 324 is supported at an oblique angle,e.g., between and including about 0° and 90° with respect to the skinsurface.

FIGS. 127-128 depict the relationship between the medical device carrier3730 and the sharp carrier 3716 (with the housing 3702 and sheath 3708omitted for sake of clarity). FIG. 127 depicts the initial position ofthe medical device carrier 3730 and the sharp carrier 3716 with thecarrier arms 3732 engaged with the sloped edge 3725 of the sharpcarrier. In this position there is no relative movement between themedical device carrier 3730 and the sharp carrier 3716. However thecarrier arms 3732 are not of sufficient rigidity or bias to counteractthe bias of the spring 3746 in order to maintain the sharp carrier inthe position shown in FIG. 127 without support from the sheath, as shownin FIG. 129. Accordingly, the spring 3746 urges the sharp carrier 3716in the proximal direction thereby displacing the carrier arms 3732radially outward as shown in FIG. 128.

FIG. 130 illustrates inserter 3700 in cross-section after a user appliesan initial downward force to housing 3702. In some embodiments, apredetermined minimum force must be used so that attachment snaps 3726advance past detent 3724.

After detent 3724 has been overcome, e.g., snap 3726 of the sheath isdisplaced radially inward, further depression of housing 3702 withrespect to sheath 3708 causes distal longitudinal movement of themedical device carrier 3730 and sharp carrier 3716, from a proximalposition towards a distal position as shown in FIGS. 131-132. Duringthis phase of insertion the interior surface of proximal portion 3708 aof the sheath remains engaged with the carrier arms 3732 to preventradial displacement of the arms 3732, and thus maintains the coupling ofthe medical device carrier 3730, on body housing 322, sharp 324 andsharp carrier 3716. As sharp 324 is further urged distally, it carriesthe sensor insertion portion 30 of sensor 14 (FIG. 17) into thesubcutaneous portion of the subject's skin S.

As carrier 3716 reaches a distal position, the on body housing 322 alongwith the adhesive pad 318 engage the skin surface S of the subject,thereby becoming adhered. Concurrently, carrier arms 3732 are advanceddistally beyond shelf 3708 b of the sheath and clear the support wall3708 a (as highlighted by focus point “A” in FIG. 132). This allowscarrier arms 3732 to deflect radially outwardly into the larger diameterdistal portion 3708 c of the sheath as shown in FIG. 133. When carrierarms 3732 deflect outwardly, shoulder portions of carrier arms 3732 areno longer in an interference relationship with the sharp carrier 3716.Thus spring 3746 is permitted to expand as shown in FIG. 133, therebyretracting the sharp carrier 3716 to a proximal position and withdrawingthe sharp 324 from the skin S of the subject while leaving the on bodyhousing 322 attached to the skin. Housing (or handle) 3702 is maintainedin the distal position and extends over the sheath in a telescopingmanner. Sheath detent or snap 3726 of the sheath 3708 can then lock overfeature 3722 of the housing 3702. Accordingly, the housing 3702 and thesheath 3708 can no longer move longitudinally with respect to eachother.

In some embodiments, the changing interaction of sheath detent or snap3726 with the housing detent/ledges 3720, 3724, and 3722 determinewhether the sheath 3708 is locked. When snap 3726 is in the pre-fireposition, ledge 3720 prevents sheath 3708 from being pulled out of thehousing 3702. In this position, detent 3724 may also impede the movementof pushing the sheath 3708 into the housing 3702. When the detent isovercome by at least a minimum force, the sheath 3708 moveslongitudinally with respect to the housing 3702 until the snap 3726snaps over housing ledge 3722. At this point, ledge 3722 prevents thesheath 3708 from being pulled out of the housing again, but from a newposition (this position may be referred to as the used/post-fireposition). Sharp carrier snap 3752 function is to hold onto thesharp/needle. In some embodiments, the sharp/needle carrier 3716 is heldin the post-fire position relative to the housing 3702 by, e.g., aninterference between the rails of the housing 3710 and the guide railsof the sharp carrier 3718 (this interference is only present once thesharp carrier is fully retracted) and/or by medical device carrierprojections 3732 interfering with the bottom/floor of the sharp carrier(See, e.g., FIG. 134). In another embodiment of inserter 3700, adhesivepad 318 may be attached to sheath 3708 prior to use. Upon reaching thedistal position, the distal surface of on body housing 322 engages theupper surface of adhesive pad 318, thereby becoming adhered to the skinsurface S of the subject.

Another embodiment of the inserter 3700′ is substantially identical tothe inserter 3700 discussed hereinabove with the differences notedherein. As illustrated in FIGS. 135-136, the medical device carrier3730′ is substantially identical to carrier 3730. However, carrier 3730′includes one or more gripping arms 3762′ including an engagement boss3764′ which is configured to engage with corresponding recesses 3766provided on the side walls of the on body housing 322. In someembodiments, the gripping arms 3762′ are configured to be spacedradially apart from the on body housing 322 in the relaxed, unstressedconfiguration. When an inwardly directed force is applied to thegripping arms 3762′, they may be directed into contact with the on bodyhousing 322.

Perspective and sectional views of sheath 3708′ are illustrated,respectively, in FIGS. 137-138. The inside of distal portion 3708 c′includes one or more ramp members 3768′, which are positioned to engagethe gripping arms 3762′ and provide a radially inwardly directed force.As illustrated in FIG. 139, in the initial configuration, the medicaldevice carrier 3730′ is positioned in a proximal position with respectto the sheath 3708′. In this configuration, the gripping arms 3762′ aredeflected radially inwardly by the ramp member 3768′ such that theengagement boss 3764′ is in contact with the recesses 3766 of the onbody housing 322. This configuration provides support for the on bodyhousing 322. As illustrated in FIG. 140, as the carrier 3730′ isadvanced distally, the gripping arms 3762′ clear the ramp member 3768′,the gripping arms 3762′ begin to deflect radially outwardly according totheir normal bias, thereby releasing the engagement boss 3764′ from therecesses 3768′ of on body housing 322. Release of the gripping arms3762′ facilitates the separation of the on body housing 322 form theinserter 3700′.

In some embodiments, the on body housing is assembled on the body of theuser. For example, the on body housing may be comprised of a mountingunit 3780 and an electronics housing 3782. The mounting unit 3780 mayinclude a mount and a sensor. In some embodiments, the sensor is atleast partially positioned within the mount and the distal insertionportion extends out of the mount. An inserter, such as inserter 3700described herein, is used to advance the distal portion of the sensorinto the skin of the subject and to adhere the mount to the skin of theuser. Subsequently, the electronics housing 3782 is mounted onto themounting unit 3780. Electrical contact is made between the electronicshousing 3782 and the sensor in order to transfer the analyte readingsfrom the sensor to the electronics housing 3782.

As illustrated in FIG. 141, the inserter 3700 is initially arranged withthe cap 3704 attached to the housing 3702. The mounting unit 3780 ispositioned in the medical device carrier 3730, with the sharp 324extending distally in a surrounding position about the sensor. FIGS.142-144 illustrate the sequence of inserting the sensor into the skin ofthe user and the attachment of the mounting unit 3780 to the skin of theuser. In FIG. 142, the sheath 3708 is placed on the skin. In FIG. 143,the housing 3702 is advanced distally towards the skin of the user,thereby advancing the medical device carrier, the mounting unit 3780 andthe sharp 324 towards the skin of the patient. In FIG. 144, uponreaching the distal position of the housing 3702, the sharp carrier 3716is released, thereby moving to the proximal position.

As illustrated in FIGS. 145 a and 145 b, the mounting unit 3780 ispositioned on the skin with the distal portion of the sensor insertedinto the skin. As illustrated in FIGS. 146 a and 146 b, the electronicshousing 3782 is inserted into the mounting unit 3780, and shown in thefinal configuration in FIGS. 147 a and 147 b.

In an exemplary embodiment of on body housing 3800 illustrated in FIG.148, electronics housing 3882 is mounted on mounting unit 3880. Mountingunit 3880 includes a detent 3884 for coupling with a recess 3886 on theelectronics housing 3882 in, e.g., a toe-in snap configuration. It isunderstood that the detent and recess configuration may be reversed suchthat the recess is on the mounting unit and the detent is on theelectronics housing. The electronics housing 3882 electrically coupleswith the mounting unit 3880 by the electrical contacts 3888 on themounting unit 3880 which are coupled to electrical contacts (not shown)on the electronics housing 3882. The sensor hub 3890 stores at least aportion of the sensor which is electrically coupled to the contacts3888.

In another exemplary embodiment illustrated in FIG. 149, the on bodyhousing 3900 is attached by first attaching the mounting unit 3980 tothe skin of the user. Subsequently, sensor 14 is positioned at leastpartially beneath the skin of the user. Electronics housing 3982 iscoupled to the mounting unit 3980 by inserting the flanges 3986 under acorresponding flange of the mounting unit 3980. Contacts 3988 of theelectronics housing 3982 are then coupled to contacts on the sensor 14in order to provide the sensor readings from the sensor to theelectronics housing 3982.

In some embodiments, the on body housing is assembled on a surface (suchas a tabletop) prior to insertion into the user. For example, asillustrated in FIGS. 150-156, the on body housing may be comprised of ahousing unit 4020 and a sensor hub 4022. The housing unit 4020 mayinclude a mount and on body electronics. In some embodiments, the sensoris at least partially positioned within the sensor hub 4022 and thedistal insertion portion extends out of the sensor hub 4022. The sensorhub 4022 is contained in the inserter, and the housing unit 4020 ispositioned in the inserter 3700. Electrical contact is made between thehousing unit 4020 and the sensor in order to transfer the analytereadings from the sensor to the housing unit 4020. The inserter, similarto inserter 3700 described herein, is used to advance the distal portionof the sensor into the skin of the subject and to adhere the housingunit 4020 to the skin of the user.

As illustrated in FIG. 150, the inserter 3700 is initially arranged withthe cap 3704 attached to the housing 3702. The sensor hub 4022 issupported by the sharp carrier 3716, with the sharp 324 extendingdistally in a surrounding position about the sensor. FIGS. 151-155illustrate the sequence of inserting the sensor into the skin of theuser and the attachment of the housing unit 4020 to the skin of theuser. In FIG. 151, the cap 3704 is removed. In FIGS. 152-153, thehousing unit 4020 is positioned in the housing support 3731, forexample, by use of adhesive patch 4028. In FIG. 154, the sharp carrier3716 is advanced distally, thereby advancing the sensor hub 4022distally and into engagement with the housing unit 4020. In FIG. 155,the sharp carrier 3716 is released, thereby allowing the sharp carrier3716 to move proximally. The inserter 3700 is removed, leaving thesensor hub 4022 coupled to the housing unit 4020, as illustrated in FIG.156.

In some embodiments, the housing unit 4020 and the adhesive patch 4028are stored in a sealed compartment 4100 as shown in FIG. 157. Thecompartment 4100 includes a lower cap portion 4104 and a cover portion4102, manufactured from a flexible material such as metal foil orplastic. As shown in FIG. 158, the lower cap portion 4104 stores thesterilized housing unit 4020 and adhesive patch 4028 therein until readyfor use. In some embodiments, the adhesive patch 4028 includes adhesiveon both sides.

In some embodiments, on body housing 4200 includes housing unit 4220 andsensor hub 4222 as illustrated in FIG. 159. The sensor may be insertmolded with mechanical contacts. The PCB in the housing unit 4220 mayinclude leaf spring contacts 4230. The sensor hub 4222 may bemechanically attached to the housing unit 4220, e.g., the electricalcontacts may function as mechanical snaps. Sealing may be provided by anelastomeric gasket. The housing unit 4220 may be macromelt or injectionmolded.

In some embodiments, on body housing 4300 includes housing unit 4320 andsensor hub 4322 as illustrated in FIG. 160. The sensor may have insertmolded contacts. The PCB in housing unit 4320 may include exposed pads.Mechanical attachment of the housing unit and sensor hub may beaccomplished by molded snaps. The needle guide may be injection moldedor overmolded macromelt of TPE (thermoplastic elastomer). The housingunit 4320 may be macromelt or injection molded.

In some embodiments, on body housing 4400 includes housing unit 4420 andsensor hub 4422 as illustrated in FIG. 161. The sensor may have exposedpads on the flag or contact portion of the sensor. The PCB in housingunit 4420 may include a SMT ZIF connector, or similar 4430. Mechanicalattachment of the housing unit and sensor hub may be accomplished bymolded snaps. The needle guide may be injection molded plastic withelastomer overmold. The housing unit 4320 may be macromelt overmold.

In some embodiments, a clamshell type arrangement 4500 is provided whichincludes a needle guide 4550 having a living hinge arrangement 4552. Thesensor may include bent metal contacts that are inserted after molding.The PCB may include PCB pads. The mechanical attachment is performed byadhesive of mechanical snap to PCB. The transponder housing, not shown,may be injection molded, UV or ultrasonic bonded.

In some embodiments, on body housing 4600 includes housing unit 4620 andsensor hub 4622 as illustrated in FIG. 163. The sensor 14 may haveexposed pads on the flag or contact portion of the sensor. The PCB inhousing unit 4620 may include concentric exposed pads 4690. Mechanicalattachment of the housing unit and sensor hub may be accomplished bymolded snaps or PSA. The needle guide may be injection molded plasticwith elastomer overmold. The housing unit 4620 may be macromeltovermold.

In some embodiments, on body housing 4700 includes housing unit 4720 andsensor hub 4722 as illustrated in FIG. 164. The sensor may have exposedpads on the flag and may also include a compressed anisotropic zebra,conductive elastomeric or similar. The PCB in housing unit 4720 mayinclude exposed pads. Mechanical attachment of the housing unit andsensor hub may be accomplished by snaps. The needle guide may overmoldmacromelt or TPE. The housing unit 4720 may be macromelt overmold.

It is understood that the subject matter described herein is not limitedto particular embodiments described, as such may, of course, vary. It isalso understood that the terminology used herein is for the purpose ofdescribing particular embodiments only, and is not intended to belimiting, since the scope of the present subject matter is limited onlyby the appended claims.

What is claimed is:
 1. An apparatus, comprising: a medical device; a sheath defining a distal surface for placement on a skin surface; a device support movable between a proximal position and a distal position that is closer to the skin surface, and adapted to support the medical device; a sharp for inserting the medical device under the skin surface and extending through a portion of the device support; a sharp support movable between the proximal position and the distal position that is closer to the skin surface and adapted to support the sharp; a handle movable between a proximal position and a distal position relative to the sheath and adapted to urge the device support and the sharp support from the proximal position to the distal position to insert the sharp under the skin surface; and a driver for advancing the sharp support towards the proximal position when the sharp support reaches the distal position; wherein the device support includes a first engagement member for releasably coupling the device support to the sharp support and a second engagement member comprising one or more movable arms for engaging the medical device; wherein the one or more movable arms are maintained in engagement with the medical device when the device support is in its proximal position; and wherein a force applied to the handle moves the sheath into the handle and moves the medical device from the device support's proximal position to the device support's distal position and inserts the sharp under the skin surface.
 2. The apparatus of claim 1, wherein the handle and the sheath comprise an interlocking configuration which prevents relative movement of the handle with respect to the sheath which is overcome by the force applied to the handle.
 3. The apparatus of claim 1, wherein the one or more movable arms are normally biased in a position spaced apart from the medical device.
 4. The apparatus of claim 3, wherein the one or more movable arms are permitted to return to the position spaced apart from the medical device when the device support is in the distal position.
 5. The apparatus of claim 1, wherein the first engagement member is released from the sharp support when the device support reaches the distal position.
 6. The apparatus of claim 5, wherein the first engagement member is maintained in engagement with the sharp support by a portion of the sheath.
 7. The apparatus of claim 1, further comprising a stop to maintain the device support in the proximal position such that it protects a user from accessing the sharp.
 8. The apparatus of claim 1, wherein the medical device is an analyte sensor comprising a plurality of electrodes including a working electrode, wherein the working electrode comprises an analyte-responsive enzyme and a mediator, wherein at least one of the analyte-responsive enzyme and the mediator is chemically bonded to a polymer disposed on the working electrode, and wherein at least one of the analyte-responsive enzyme and the mediator is crosslinked with the polymer.
 9. A method of using an apparatus, the method comprising: holding an apparatus comprising a medical device, a sheath defining a distal surface, a device support comprising one or more arms adapted to support the medical device, a sharp extending through a portion of the device support, a sharp support adapted to support the sharp, a handle movable relative to the sheath, and a driver for displacing the sharp support; disposing the distal surface of the sheath on a skin surface with the one or more arms of the device support maintained in a first position in engagement with the medical device; displacing the handle in a first longitudinal direction such that the sheath moves into the handle; displacing the sharp support in the first longitudinal direction, the sharp support displacing the sharp and the medical device; inserting the sharp and the medical device under the skin surface; releasing the driver; and displacing the sharp in a second longitudinal direction by the driver; wherein displacing the handle in the first longitudinal direction displaces the device support in the first longitudinal direction and inserts the sharp and the medical device under the skin surface.
 10. The method of claim 9, wherein the first longitudinal direction is from a proximal position to a distal position, and the second longitudinal direction is from the distal position to the proximal position.
 11. The method of claim 10, wherein the sharp is displaced towards the proximal position when the sharp support reaches the distal position.
 12. The method of claim 11, wherein the handle is maintained in a distal position when the sharp support is displaced to the proximal position.
 13. The method of claim 9, wherein displacing the handle in the first longitudinal direction comprises overcoming an interlocking configuration between the handle and the sheath by applying a predetermined force.
 14. The method of claim 9, wherein inserting the medical device under the skin surface comprises releasing the medical device from the device support.
 15. The method of claim 14, wherein releasing the medical device from the device support comprises allowing the one or more arms on the device support to displace radially outwardly.
 16. The method of claim 9, wherein the medical device includes an analyte sensor comprising a plurality of electrodes including a working electrode, wherein the working electrode comprises an analyte-responsive enzyme and a mediator, wherein at least one of the analyte-responsive enzyme and the mediator is chemically bonded to a polymer disposed on the working electrode, and wherein at least one of the analyte-responsive enzyme and the mediator is crosslinked with the polymer.
 17. A system, comprising: a medical device; a sheath defining a distal surface for placement on a skin surface, the sheath having at least one biased retention feature; a device support movable between a proximal position and a distal position, and comprising one or more movable arms adapted to support the medical device, wherein the one or more movable arms are maintained in engagement with the medical device when the device support is in its proximal position; a sharp extending through a portion of the device support; a sharp support movable between a proximal position and a distal position and adapted to support the sharp; a handle movable between a proximal position and a distal position relative to the sheath and adapted to urge the device support and the sharp support from the proximal position to the distal position to insert the sharp under the skin surface, wherein advancing the handle from the proximal position to the distal position comprises applying a minimum force to overcome the at least one biased retention feature to allow distal movement of the handle relative to the sheath; and a driver for advancing the sharp support towards the proximal position when the sharp support reaches the distal position; wherein the device support includes at least one feature adapted to operatively engage the sharp support; and further wherein the minimum force applied to the handle moves the sheath into the handle and moves the medical device from the device support's proximal position to the device support's distal position and inserts the sharp under the skin surface.
 18. The system of claim 17, wherein one of the sharp support and the device support includes at least one retention feature.
 19. The system of claim 18, wherein the retention feature is disposed on the device support.
 20. The system of claim 18, wherein the sheath maintains the retention feature operatively engaged between the device support and the sharp support until the device support is advanced to the distal position.
 21. The system of claim 20, wherein advancement of the device support to the distal position releases the retention feature to allow proximal movement of the sharp support and the sharp relative to the device support.
 22. The system of claim 18, wherein the handle is maintained in the distal position when the sharp support is advanced to the proximal position.
 23. The system of claim 17, wherein the medical device includes an analyte sensor comprising a plurality of electrodes including a working electrode, wherein the working electrode comprises an analyte-responsive enzyme and a mediator, wherein at least one of the analyte-responsive enzyme and the mediator is chemically bonded to a polymer disposed on the working electrode, and wherein at least one of the analyte-responsive enzyme and the mediator is crosslinked with the polymer. 